This is pretty awesome for some types of hangs. I would bet most hangs developers experience are because of locking on SessionState. IReadOnlySessionState is your friend.
I've run into this a lot and ended up changing a lot of the internals of how session state works and have _mostly_ eliminated the issue for us. Granted, you still run into it if you have 2 pages running at the same time, but we see it where sometimes it just doesn't release the state (and it was happening fairly frequently)
That's certainly a good one! One of the things we'll do to help resolve the hang is to identify where blocking is happening. This will pinpoint the session state module in AcquireRequestState as the culprit.
Although, I also have to say, IReadOnlySessionState wont help you a whole lot in a high volume site because the SessionStateModule will still connect to SQL server to keep the session alive in ReleaseRequestState. So, best advice I would give is to use the new AppFabric Cache based session state or go stateless.
http://darrenkopp.com/posts/2013/04/10/Playing-with-fire-Opt...