my experience
I have to use a cliché, but I really have to use the classic response to the question of, "which computer should I get?" The answer being, of course, "what are you going to use it for?"
Are you doing lots of video/audio editing? Lots of gaming? Or just the basic web/email/office combo?
My Experience:
I have a 1.25 Ghz Mini G4, that i bought used off eBay around September of 2006 (that's about 15 months ago). I'd made the switch from Mac to PC for a couple of years because it had become too difficult trying to bring files back and forth between my PC at work and my Mac at home. I wanted to come back to Mac, but was unsure if I'd like OSX (my last Mac was a PM6500 running System 7.6.1), and I didn't want to buy a new monitor and peripherals, so I went with a used Mini. It cost me less than CAN$400.
I'm pretty happy with it, and I have no plans to replace it any time soon, but it does get sluggish from time to time if I run too many applications at the same time.
I use it mostly for basic home office functions. It came with MS Office installed, but NeoOffice would work just fine for me if I didn't have MSO.
The only game I play on it is World of Warcraft, and it doesn't run very well. I have to really cut back on the graphics to get decent framerates.
I bought a 75GB firewire hard drive off eBay to supplement the 40GB that's built-in. That was critical in order to hold all the music I have in iTunes and the photos I have in iPhoto. I also keep meaning to play around with iMovie more, but never get around to it.
I used the cheapest USB keyboard (a Dynex for CAN$9) and mouse (again, a Dynex, CAN$9) until recently when I picked up a wireless Fellowes keyboard and mouse, also for CAN$9. I would avoid the Mighty Mouse like the plague, and I don't much like Apple's keyboards either. They haven't sold a decent mouse or keyboard since the crap that came with the first Bondi Blue iMac.
The monitor is a 15 inch Dell I had lying around gathering dust. I keep meaning to get a better monitor, but there's always a more important expense that needs the attention of my wallet.
The point of all this rambling on is that the computer does the job for me that I need it to do. With all the new open source software available for OSX, I've never again run into the problems I used to have about working on files from my office PC. I have always been able to find a Mac program that works, and now I've even been able to purposefully install cross-platform software on the office PC anyway.
What Could Happen in January:
I would be very surprised if Steve Jobs discontinued the Mini. The Mini was his third (or was it fourth?) attempt at popularizing a small-box computer (the NeXT, the G4 Cube, then the Mini. Am I forgetting a fourth?), and it seemed to finally work this time.
I'd love to have access to Apple's sales data, but I bet their strategy of marketing the Mini to PC users who were curious about Macs but unsure about making the leap has paid off. I mean, it's why I bought my mini. The concept of having a second computer that's so small that it sits on top of my PC tower and uses the same monitor/mouse/keyboard was VERY appealing to me.
There are only two serious gripes I have with the Mini: One is the difficulties in upgrading it. Of course this is largely unavoidable with the small-box concept, but Apple made the conscious decision to make the case so dang difficult to open that even adding more RAM is a major pain in the butt. The second is the lack of USB ports. It only has two, which you need for the mouse and the keyboard. As such, a USB hub is a required purchase even if you only want to add a printer.
(I've never understood why Apple wouldn't include a third USB port for a printer. It would make sense if they sold an Apple-branded USB hub as a way of squeezing a few more dollars out of you, but they don't, so why bother frustrating the end user when Apple doesn't benefit financially?)
Now, MAYBE, just MAYBE, Mini 2.0 is sort of Apple's response to the One-Computer-Per-Child $200 laptop, or the Linux-on-a-USB-key phenomenon? Maybe the Mini 2.0 is even smaller, like the size of a cigarette box (or an iPhone?) or something like that. It's already a reality in the Linux world (Examples:
http://www.gumstix.com/waysmalls.html,
http://www.picotux.com,
http://www.aleutia.com,
http://www.linutop.com) If would seem to be a logical next move in Steve Jobs' quest to be the ultimate guru of the "next big thing".
I mean, if you think about it, there's very few technical obstacles for a Mini 2.0/iPhone device that blends the best of both worlds. Pack a full-featured version of OSX onto an iPhone and start marketing adapters to connect all your peripherals (including a VGA monitor!) via Bluetooth. Apple still hasn't officially revealed what kind of processor is in the iPhone, AFAIK, but it's supposed to be a 700 mhz ARM processor.
This idea probably WON'T actually happen, considering how much Apple hobbled the capabilities of the iPod Touch, which easily could have been a more-than-full-featured PDA to take on Blackberry and Palm, but came up WAY short (the Palm T/X kicks the iPod Touch's ass!). Steve Jobs really doesn't want end users to have too much control over the iPhone, and a Mini 2.0 based on the iPhone platform would unavoidably mean letting the end users at the guts of the machine.
The Bottom Line. Wait or Buy Now?:
1) Just how dead is your PC? Dead-dead, or just mostly-dead?
2) What do you need the computer for? Mission-critical work assignments where you simply can't go another month without a computer? Graphics-intensive work/games where horsepower matters and another month's wait won't kill you? Or just playing around with Facebook and WoW, and a month of getting away from the computer and playing out in the fresh air would do you some good anyways? ;-)
3) How much time are you able to devote to learning OSX? It's not difficult by any stretch of the imagination but, contrary to what the ads tell you, there IS a learning curve. Trying to get non-standard (read, not Apple-approved) peripherals to work properly can sometimes be frustrating.
4) How much money do you have to spend? I really like used/refurbished. I haven't bought a bona fide "new" computer since 1997. I've had five used/refurbs since then, with no major complaints.
