It's pretty incomplete for parts of the world, and certain applications require accuracy (or at least completeness). The answer, of course, is to contribute, but when your core business isn't mapping that's hard to propose as a viable fix.

Parts of the world in my case ~= Sydney, which has a decent number of geeks per capita to contribute. OSM is wonderful, but has a way to go before it's a viable solution for everyone.

Second that. Google maps are surprisingly bad in a number of first-world countries like France or Israel; OpenStreetMap are very very detailed. I don't think Bing maps would be better than either of those.