Personally I'm going with Unity and targeting mobile (iOS / Android). I don't really care about publishing to the web right now (Unity Flash doesn't work too well because the full feature set of C# .NET is not supported) but when Unity adds support for WebGL (which I'm sure they will) it might be a good option.
If I wanted to make hardcore games or games with higher graphical requirements I would publish to PC / Mac and not to the Web.
So, right now I don't see a compelling reason for publishing to the web or developing in WebGL.
edit- I'm speaking from a business perspective. If you just want to make cool stuff deployable to the web, then go for it =)