When you're the only player in the market with a given toolkit, you have to be on the top in your marketing and reach critical mass quick. webOS faltered for this reason. On top of that, it's toolkit (unless I'm looking at it wrong) seems centered around HTML, CSS, and Javascript which strike me as not being terribly -fast-. Anything beyond that forces you into their Plugin Development kit, which isn't (easily) portable.

It's for this same reason I think Bada and whatever Motorola is planning will falter. Yet another API, yet another toolkit, and only one vendor backing it. Too much fragmentation, which is what Nokia and Intel moved to avoid.

Whereas with Qt, MeeGo is deploying a toolkit that's in wide use already, and available on pretty much every platform in existence. MeeGo is not bound to Nokia, either, which means that (like the Kernel itself) third parties can pick it up and use it without appearing to be playing second fiddle to Nokia.