Tomas Kalibera from Charles University in Prague has a project that tracks the performance of the Mono runtime, see his project page here.
Their Mono Performance testing project tracks performance improvements and regressions on a number of tests and tracks the corresponding changes in the Mono source code that caused the change.
Any tests that are part of the mono/tests also become performance tests, the status can be tracked in the following page 24 hours after they are commited: http://nenya.ms.mff.cuni.cz/projects/mono/benchmarks/rtests.phtml
XMLMark is a test suite for XML stacks (Java and .NET), the paper is available here.
An easy to use port for Mono on Linux (with the patches described in the paper plus a Makefile ready to run) is available here.
A progress report since we found this paper with graphs is maintained by Atsushi here.
The Language Shoutout compares a set of simple benchmarks with implementations on different languages and frameworks, it is available here