I have had my iMac Rev A 1.6 with Geforce FX for around 8 or 9 months now and I am not selling it to get a new one. I have had no problems with it either. The reason I will not sell it to get a new one is:
I want to get some usage out of it for the next couple of years and by the time I do that, the new iMacs will be even better and the intel version will be out.
It is not long since they were updated, and I played the updating every 10 minutes game when I had PCs - I certainly did not invest money in a Mac to start playing that expensive game again. It took me a while to realise that today's latest and greatest is yesterdays history
Also, this perfectly suits my needs for what I use it for - there is no need for quite a long time to update it.
I purchased a three year warranty on it which includes accidental damage, so, IMHO, I would be foolish to lose even more money on the warranty just to sell it to get a new one.
IMHO I see no reason to buy a computer every 4/6/8 months or so just to lose money and get a better model, and then lose money again on that model to get an even better one when they are updated again..... I really do not see the point unless purchasing the update is necessary to needs.
No detriment to those who do BTW, because I suppose if you have the money to do that, then that is fine - but I have not got the money anymore as I invested everything in the three Macs I already own.