This is great. I hope they make this available for web apps because we've got 45 second warmup time and CPU spamming due to the massive size of the work the JIT has to do when we deploy. Total pain.
I imagine this would help them keep costs down on Azure as well.
From my experience, much of an ASP.NET web app's start time is not so much the JIT-ing but before that, when the ASP.NET runtime compiles pages/views (aspx/cshtml etc) into *.cs then DLLs. Pre-compiling can mitigate this.
Larger EF models can have quite an impact.
Also if you use New Relic, it can seriously affect startup time too.
Yes and no. We ship our views as content as we have a custom UI front end that isn't razor or asp.net. The startup time for us is compiling NH proxies and the fact that our bin dir is huge:
I imagine this would help them keep costs down on Azure as well.