I probably will. I plan to buy a mini as soon as the anticipated update occurs. Since its hard drive (or any mobile drive) will be far from large enough for my needs, I'll use an external drive. This is not the ideal solution but it'll do I suppose.
I'm in the same boat. I'm waiting for a mini with x3000 which should be the next system or the one after that (unless the next machine has something other than an x3000 that isn't a GMA950, but I digress). I already have a 120gb FW drive, but I am hoping against hope that Apple adds an eSATA port to the new mini. Seems pretty reasonable, imo.
If they don't, I am SERIOUSLY considering making my own eSATA port, like has been seen online. I'm already giving my wife my G4 mini, and she'll want the extra drive anyway, so I could snag a 4000gb SATA drive (can't believe these are down to <$100 already) and another mini-stackable drive case and do it. That system would be pretty close to perfect, for me. C2D, x3000 (which is looking more and more like it might actually live up to the hype surrounding it) GPU, 2gb RAM, 400gb external SATA with no drive in the mini which would create some extra airflow room and reduce heat inside the machine, ensuring that the already nearly silent operation stays that way...
Actually, I just came across this page,
http://www.amug.org/amug-web/html/amug/reviews/articles/mini/dock/, which is brilliant. If it weren't for the GPU in the current mini I'd likely grab a refurb or used low end of the current model (1.66ghz CD/60gb/CD $519 from Apple) part out the drives and RAM, get a snazzy case, put a 400-500gb SATA drive and a 8x+ DVD-RW, and 2gbs of RAM in it. Probably end up running me, what, $519 for the mini, minus $90-100 for the removed parts, and add another $275 for new drives/RAM... plus whatever I feel spending on a case (lots of cool older PowerMac cases out there - like the mirror door G4's, which are hot imo... the cube would be fantastic if it weren't for the fact it uses a slot loading drive) and I've STILL spent less than the current high end mini.
Hell, now that I am looking at it, I might do that even WITH the crappy GPU.