Watching the maemo-developers mailing list, I'd say the Maemo team is still months away from a polished final release, so if you want something sooner rather than later, go N97.

The N900's OS, I think, will look "swishier" and very next-generation, with lots of transparency, 3D effects, swishing and swooping windows, etc. That tends to appeal to gadget hounds.

I think the N900 will be a very nice device, nicer to use than the N97, and probably with a very good set of apps out of the box...

...but it will really shine for all of the edge cases that excite us geeks; it will be able to handle open codecs (like ogg, flac, etc), it will have a command line, you'll have all the freedom of the current tablets to hack away at everything and anything....

But that isn't interesting, as you said, to gadget hounds.