Perhaps you know that Virtual Earth-3DVia by Dassault Systems is our software for creating models in Virtual Earth 3D; perhaps you didn't. I haven't seen many models built out, but what I've seen have been okay - just okay. If you have some sweet models that you're proud of send the link to your collection. I had issues installing 3DVia to the point that 3DVia just rendered a black screen. My RAM had vanquished and I had to work in a subzero fridge so my CPU didn't catch my paltry video card aflame.
3DVia is a free download from Microsoft. You can get it on Live Search Maps when you click 3D in the navigation control (there's an option while you install the 3D plug-in); or, download it directly from the Virtual Earth-3DVia Download Page. In the meantime, I'll watch this video of what 3DVia can do and eat my sour grapes. In fact, the Dassault guys made the models (the new Microsoft France Headquarters) with 3DVia so they showed me who's boss. Um, can you "sick?!?"
I have an XPS with 256MB GeForce 8600 GPU (8800 not yet available) on order. 4GB RAM. 2.6Ghz Processor. You don't have to get something with this much brute force, but I plan to do quite a bit more 3D work in the next few months so I'm making the investment now...well, Microsoft is.