This is a nice if unspectacular upgrade. All three programs have been improved. It isn't the have-to-have change that iWork 08 was, but I'm happy with it. All three programs include more of Apple's slick templates, integrate with each other better and sport useful new features.
The biggest changes are in Numbers, which makes sense as it's the newest member of the suite. Apple claims 90 new functions. No longer being a power spreadsheet user I don't need all of them but the much improved charting is appreciated. Numbers also integrates with Pages for page merge, so you can use non-Address Book contact lists. That was an obvious omission in the previous version and is honestly useful. Also Numbers charts and tables inserted in Pages and Keynote will change if the spreadsheet is changed. Again an obvious omission in the last version that's been addressed. Don't move your files, though or you'll lose the links. As before, Numbers is an easy to use and attractive program for normal people. It isn't a replacement for Excel for power spreadsheet users. Thank goodness I don't have to do that kind of work any more.
Keynote has some stunning new transitions and effects that extend the sheer elegance of its presentations even farther beyond Powerpoint. If you do a lot of presentation work, Keynote is worth the price of the suite all by itself. And there are some new templates that reflect Apple's excellence in presentation.
Choosing templates in all three programs is now a bit easier with the improved template chooser.
Pages is the program that I use daily and it has a couple of new features that I appreciate. The full screen mode, that blacks out background distractions is welcome. That's been around in a number of programs before and I've gotten used to using it. The Pages implementation is a bit different, but done with Apple's typical elegance. The outlining feature introduced here is brilliantly implemented. It's the killer feature for me in the suite. I appreciate all the others but use this often.
There are some other new Pages features like the ability to work include formulas and integrate with Endnotes that I haven't used yet. This is a step in the right direction. Hopefully Apple will also include endnote compatibility Bookends, which I do use in an update. Pages still lacks some of the high end features of Word and probably always will. On the other hand it is more pleasant to work with and stable. Compatibility between Windows Office files and iWork seems to be as solid as it is between the Windows and Mac versions. Since Microsoft dropped macro support on the latest version of Office for Mac, I've switched totally to iWork and haven't looked back. This version of iWork just makes me happier with that decision.