While everyone is putting forward about how great Google Gears (GG) would be, pushing it to include "mesh" and "peers" [I assume is peers to peers (p2p) is a bit over the edge.
I agree that GG would potentially be able to increase the capacity to serve more concurrent users in a collaboration system. However, creating a browser-based solution do "mesh" or p2p is a totally different ball game. First of all, for security concerns, scripts will not be allowed to call arbitrary servers (AJAX is no exception) and hence one user logging to multiple "collaborating" servers is a technical challenge. Establishing connections to other peers without an intermediate server acting as a post office, meaning each user is both a client and a server at least after connection is established, is even more difficult.