My favourite telephoto lens for the MFT system is this one. I find that the optics are better than the newer 40-150mm f/2.8 PRO lens (not that that lens is bad, it just isn't as good bokeh wise as this one).
The tripod mount is removable and when you take this off as well as the somewhat large hood, it fits into a moderately sized camera bag without much fuss, which gives you a very versatile wedding lens that has a smaller form factor than the typical 70-200mm f/2.8 for 35mm systems. If you also can find the Olympus 1.4x teleconverter for this you will get an extra 40% magnification and as far as I am concerned there is no noticeable loss in image quality.
Not the most heroic looker when fully zoomed (the barrel extends), but when IQ is more important to you than what a lens looks like, this one will make you very happy as an MFT shooter (using a dual AF system camera body like the E-M1).
Mass (g): 995
Length (mm): 15.7
Filter (Ømm): 67
AOV ˚: 24-6.2
Min. Focus (mm): 120
Rating (1-10): 9