Wait a minute, if you are planning on waiting up to four months anyways???? Why not wait it out. It has been FIVE MONTHS since the unibody MB was released. Do we really not expect a CPU "speed bump" update? It may not happen, but if you were thinking of waiting four months, why not give it a chance...
I have read a lot of posts here with people saying Apple is not going to update the MB and MBPs every six months but instead annually... I don't know about that. Look what waiting a year got Apple when it came to the iMac... people quit buying the iMac because they were waiting for an update. If you look back over the history of the last three years of MBs and MBPs, nearly every six months there is an update.
Granted, any update we would THINK would probably just be a speed bump... BUT, I imagine that Apple may just rethink the FireWire bit... Look, it has come out with TWO brand new versions of CONSUMER products and included a FireWire 800 on the lowly Mac mini... We all thought that Apple had abandoned the FireWire for consumers. Apparently all of the complaints really added up and Apple thought they better include FireWire 800 on the Mini and even the iMac. With its position on the MacBook, everyone thought maybe Apple was going to get rid of FireWire completely for consumer models... MAYBE JUST MAYBE FireWire will make it back on the very next revised MB??? Personally, I don't care. One, I don't use FireWire and Two, I don't use the MB.
But if I were in the market to buy a MB within four months, I think I would wait out the four months and see what happens. Maybe no update. Maybe a "small speed bump" update. Maybe a RAM 8 GB configuration limit update (what happened with iMacs). If I were a recent MBP unibody buyer I would be PISSED OFF. Look, the MBPRO only supports 4 GB of RAM, yet the lowly iMac (CONSUMER) model supports 8 GB. If I were a MBP buyer, I would be screaming at Apple to provide a fix and support 8 GB of RAM on the 15.4" MBP. Heck it may even happen on the MB, since it happened on the consumer oriented iMac.
The point is we never really know with Apple. If I had to bet money, I think I would tend to believe the whole "September" is back to school time... BUT, I also tend to believe that Apple needs to keep updating its notebooks every six months to stimulate continual purchasing instead of seeing slow downs by people waiting for the six month speed bump update.
So, if you plan to wait FOUR MONTHS, wait four months and see where we are. In four months, we probably or possibly will have Snow Leopard. In four months, we may have a speed bump update. In four months we may have a FireWire port on the MB. In four months, the MB may support up to 8 GB RAM (which in the future would be a cheap and easy way to make your MB last an extra year or two). In four months, we may have nothing more to show and you may end up waiting a month longer or two...
But really, in the end, waiting is half the fun. Waiting and wanting makes us try to achieve goals and meet criteria we set for ourselves. Waiting for technology USUALLY equals a better result. Waiting could be a really great thing. And waiting will keep you coming back to Mac Rumors checking to see what happens... what is rumored... what we think is next... what insiders think is coming... waiting isn't always a bad thing... I have been waiting for a netbook and waiting for a Mac Media Server and waiting for a new AppleTV and waiting for a Mac mini (which was in case the Mac Media Server didn't happen), and waiting for a new iPhone, and of course waiting for the MBA rev C with 4 GB RAM and a 256 GB SSD and a "silky smooth" glass trackpad... waiting is half the fun.
Why not wait four months and if something happens sooner, go with it then.