QUOTE
has Apple got something coming out bigger and better very soon?
Absolutely! It will be available about three months
after you buy whatever Mac.
As far as upgrading/transition, the longer you wait the more difference there will be. If you buy before Snow Leopard comes out, you'll have Leopard installed. That means you can still run most PPC apps, although slower. After Snow Leopard (or soon afterward) new machines will have the newer OS installed and, as I understand it, will support only Intel apps. Your biggest expense, of course, will be getting upgraded software that will be able to read/use your current file formats.
The transition itself, should be pretty painless, especially from 10.4 to 10.5. I've heard good reports about Migration Assistant and, as long as you old machine is working, the transfer of most data and personal info is quite easy.
My general rule for getting a new machine is to do so when I see that I can get more done, with less hassle than with the current machine I have. Speed increases are always nice, but you may not actually see them as much as you think unless you are doing highly cpu intensive tasks. Drives are almost always larger, that's never bad. Any machine will last only a certain number of years, obviously, a new machine will be covered, automatically, by the new warranty - one less worry.
The one thing I recommend
against is, letting ads convince you that what you
want is what you
need. Think about what you are doing, how long it takes and what you might want to do in addition. Will the computer be used for a business? Can your work with it pay back your capital investment in a reasonable time (less than a year)?
I'm sure you'll get plenty of advice here, but remember, it's your money that will be paying for this new Mac! And some advice, especially mine, is sometimes not worth the electron used to get it!