Basically Google seems to have problems of horsepower right now, as it delayed a more massive StreetView launch due to the large amount of resources it would mobilize.
As a result, although they have already have shot big parts of France (for instance) , they're releasing only major cities.
In addition to that the launch of the new iPhone firmware compatible with StreetView will strain their servers even more.

Thus, and Platypus being supposedly a resource intensive app (unless it's done in a clever incremental way, and possibly distributed one), I don't think they're likely to launch it any time soon. Should they do it, it will either be invite-only or billed-service.

Yes, Google has bandwidth problems (read my French article http://www.zorgloob.com/2008/10/street-view-6-questions-6-rponses.asp). Yesterday was another example: why do you think Google released *progressively* Gmail Video Chat? ;-)

It's a P2P thingy, so I guess it's not as much of a hurdle than a Google based, shard replicated filesystem

In the meantime, Microsoft offers 25 GB of free space with SkyDrive:
http://skydriveteam.spaces.live.com/blog/cns!977F793E846B3C96!11672.entry
Now they only need to offer a public API.

What makes you say that GDrive will be P2P (peer-to-peer)?!

No I don't think it will. I say they could launch it only if it was a P2P thingy. But Videochat is P2P. That's why they could afford to launch it now.