1) Don't play the "what if" game. If you know what you'll be doing, buy what is out today that works for you and DON'T look back. There will always be something better, as soon as tomorrow or next week/month. Do yourself a favor and make up your mind to be happy with what you buy, or you are sure to suffer needless buyer's remorse, it's just a matter of time. Macs hold their value very well. If you are concerned about a good buy, look on ebay. Early adopters will sell there macs shortly after, or just before a rumored release. Remember, Applecare IS transferrable, 3 years on the machine, regardless of the owner.
2) I've switched to all macs within the last 2 years. I can say short of gaming, I can do everything that I need to do, and with fewer headaches. I do use Parallels, there are things that I just have to have windows for in order to work. I don't use bootcamp, and since I'm not much of a gamer, the idea of rebooting to run a windows app I need for 10 minutes is just crazy. The old PowerPCs are still a good value, but windows performance on the intel chips is a good thing, much more practical than Virtual PC.
3) I went the hacked OSX86 route for a while. You really don't get the full experience, and while it can be stable for the most part, every update is a pain, and I spent a lot of time trying to get things to work. If you are into that, Linux is a better choice IMO. If you want a hassle free machine, as hassle free as any, then get a real mac. OSX86 is a novelty, but there are concessions, things that don't work quite right, and the knowledge that what you are doing is technically illegal.