You would imagine Chelsea will play in a similar style to the semis, sit back, defend and try hit them on the counter.
I would expect Bayern to dominate possession as they did against RM but they defended the counter quite well in my opinion.
RM's counter is much more potent than Chelsea's.
I think the major difference between Bayern and Barca, is that Bayern are not as one dimensional (as Barca were in the semis), they like to attack from wide positions and through the middle.
Chelsea will not be able to simply swamp the centre with bodies, Bayern will stretch them out.
Bayern have 2 less games before the final, so could be fresher but Chelsea do have a bigger squad.