Best way to learn Signal Integrity
Start with the two books by Lee Ritchey (Right the First Time vol I and II). Then read Eric Bogatin's book. The reason I like those books are that they are so hand-on and free of unsupported "theories".

In my SI courses I often use SigXplorer from Cadence as "the" tool and you can do a whole lot of SI analysis with that tool alone. That and Hyperlynx are probably the two most used tools.

Predicting the future is always difficult, but by now it's clear that pre-route SI analysis is a key skill and rule based layout is a key skill now and in the future. 

PS: You can easily find Lee Ritchey's first book as a pdf on-line for free or very cheap (fully legal).