I think that OnLive is a very bad example to use when talking about web gaming, because, well, it wasn't web gaming. It was an attempt to shoehorn gaming platforms onto the web- little surprise that it failed.
That said, web gaming right now isn't good. But if WebGL becomes popular then there's no reason for it not to become a perfectly usable platform.
That said, web gaming right now isn't good. But if WebGL becomes popular then there's no reason for it not to become a perfectly usable platform.