I tried Google maps on the Pre 3 and it didn't render right. It only rendered half the screen and the images were too small. Clearly not ready for the resolution change. Also durig the enyo demo, when he added a map widget in ares, it wasn't using google maps images. It looked like bing or something else.
Edit:Yup just confirmed it, its definitely a bing map.
I'm much happier with my EVO simply because the integration with Google far outweighs the better multi-tasking ability of the Pre. Well, that and the fact that WebOS never ran smoothly on my original Pre (too many cards, etc.).