The new Pages in iWork'08 seems to have some uncomfortable bugs: it claims quite a lot of memory, hogs the CPU, and often freezes my whole OS X GUI. To put it mildly: I have to restart Pages several times a day to make it usable.
It looks like the memory management of Pages 3 is b0rked. While I'm typing this, Pages is trying to shut down (now for over a minute!). It is using one core of my CoreDuo, and about 70-80% of the time it is spending time in the kernel, increasing the real memory usage (now 471 MB).
The shutdown has now finished, in over 5 minutes!!! AAAARGH.