OK, so I've just installed new shiny VS 2015 and started to regret about that. There's a new feature called Diagnostic Tools where you can observe memory and CPU usage, also this window shows IntelliTrace events. While the feature is nice to troubleshoot specific memory- and CPU-performance related issues, I don't want to always spy on those metrics as I used to solve problems only when they appear. So I turned off Diagnostic Tools - and voila, I can't see IntelliTrace events anymore, because VS 2015 shows them in Diagnostic Tools window, which I disabled.
Is there anybody who knows how to get IntelliTrace window back?
You can disable CPU Usage and Memory Usage tools in Diagnostics Tools window by unchecking them in Select Tools drop-down menu (see here). After that Diagnostics Tools window will show only IntelliTrace data.