I've been planning to do something similar, but at run-time where the last known value of each variable is shown. This would complement my stuff nicely - https://github.com/swax/CodePerspective
Just a quick caution from someone who has been building similar tools (not as fancy though), is that runtime instrumentation can often severely slow down the main app to the extent that people often don't want to run such tooling.
There are a bunch of settings where you can define the level of tracking. The state tracking is very low overhead though because it's on demand. So if you run your asp server through code perspective and then deploy it, you can at any time connect to it with the viewer and check out the current state information for all the classes.
Just a quick caution from someone who has been building similar tools (not as fancy though), is that runtime instrumentation can often severely slow down the main app to the extent that people often don't want to run such tooling.