It seems that Microsoft has come up with a way to introduce HTML5 WebSocket into Internet Explorer. HTML5 Labs is a Microsoft site providing prototypes for the more unstable aspects of HTML5 and other web standards.
What this comes down to is a set of plugins that upgrade IE8 or IE9 to include the new feature through a manual process. So far HTML5 Labs has prototypes for IndexedDB and WebSockets.
It is good to see Microsoft providing this level of support for the upcoming browser technologies. It gives developers a chance to try them out in IE, this is important since the specifications for these features are somewhat unstable it is always good to have multiple implementations to test against to avoid the possibility of relying on a quirk of one implementation. It also shows the Microsoft are not just ignoring these technologies, so gives some hope of them being fully supported at some point in the future.