Haven't heard about DTM cars going Le Mans(BMW already had a GTR one in the ALMS and the 24hrs of the Green Hell), but they made an agreement with the Super GT Series, so DTM cars could also run there. Not sure from when on.
they finished four days of testing, wonder why there are so few images of these tests around, official homepage shows none. Results were mixed, everybody trying to get as many laps under their belt as possible. mercedes were 0.3 faster than Audi who in turn were 0.3 faster than BMW, but before end of April, that counts for nothing. There's a nice vid on DTM homepage about the tests: