There is WebRTC, which is, IIRC, run over UDP. If you don't care about P2P, you could conceivably use it between the server and the client, eliminating most of the signaling pain.
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It would be pretty dangerous to let HTML5 access the networking layer :-)
I'm sure in browser multiplayer games will benefit from HTTP over UDP as well.
There is WebRTC, which is, IIRC, run over UDP. If you don't care about P2P, you could conceivably use it between the server and the client, eliminating most of the signaling pain.