Well I think that both PPC and Intel CPUs have their advantages and their disadvantages.
In the current situation ref Mac processors, on the PowerPC side you have a group of processors that are capable (more than?) in speed and greatly tested and proven.
On the Intel side you currently have a group of chips which are new, pretty unproven, yet seemingly quicker than the PowerPC chips.
So in essence this is a battle of Old Vs New and it's a battle of 'Proven and Fast' Vs 'Un-Proven and Very Fast'.
If you buy a Mac with a PowerPC chip in it now, you're buying a Mac which is proven and tested, reliable and fast.
If you buy a Mac with an Intel chip in it now, you're buying a Mac which is fairly un-proven and un-tested, seemingly reliable and very very fast. Essentially though, you're buying into NEW technology and you need to be accepting of the good and the bad that comes with that.
Personally I believe that anyone who buys EITHER of these CPU based Macs is going to buy a really great computer either way and that both will be supported for a long, long time.
I certainly don't believe that a PowerPC chip is better than an Intel Chip, but at this stage I wouldn't like to say the Intel chip is better either. It may be faster.....In areas....But really it's all swings and roundabouts.
Certainly though, when the Intel chips are more proven, tested and their architecture is fully taken advantage of by software developers, I believe the answer to your question will be very simple.