After reading Scott Guthrie entry about the upcoming improvements for .NET Client Applications, I thought inmediatly in InfoPath:
"This summer we are going to ship a servicing update to the CLR that makes some significant internal optimizations in how we optimize our data structures to cut down on disk IO and improve memory layout when loading and running applications. Among many other benefits, this work will significantly improve the working set and cold startup performance of .NET 2.0, 3.0 and 3.5 applications and will dramatically improve end-user experiences with .NET-based client applications.
Depending on the size of the application, we expect .NET applications to realize a cold startup performance improvement of between 25-40%. Applications do not need to change any code, nor be recompiled, in order to take advantage of these improvements so the benefits are automatic."
I will need to test it with different InfoPath forms!
If you have some perf numbers, just send them to me!