MacBook is probably fine for your needs, they really are very fast, lightweight and portable computers. I'm running a MacBook 2GHz, 512RAM and 60GB HD (Coreduo obviously). I for one am not bothered by the new 64bit Core 2 Duos, firstly because it's going to be years and years before 32bit processers are phased out and secondly, I'm quite certain my MacBook will be suffice for the next three years or more. Moreover, the next OSX Leopard (despite being designed with 64bit processing in mind) is going to run even quicker that OSX Tiger.
Regarding the MacBook Pro, then if someone offered me a straight up swap with my MacBook, I'd definitely take it because the Pro's are better notebooks. That stated, I doubt for my requirements they are worth the extra cash if indeed I had to pay. They are only quicker in the graphics department and I use my computers for audio productions, not intensive graphic design or computer games (have a PC for them!).