Both from 43rumors above and via a source of my own, it seems there are two new X type zooms coming from Panasonic next year. These are the previously rumoured 12-35mm f/2.8 and 35-100mm f/2.8 lenses. Both with f/2.8 throughout.
With the X design, these should be around the size of the current 14-42mm and 45-200mm lenses. So pretty small and light for what they are, which is m4/3 versions of the 24-70mm f/2.8 and 70-200mm f/2.8 35mm / FF lenses which have been regarded as the "workhorses" of "pro" photographers for some time now. These are the particular favourites of many wedding and event photographers.
In many ways, they seem a strange choice for Panasonic. I wouldn't have thought that they add any particular benefits to the system. Particularly with the release of the three fast primes this year. The 12mm f/2 , 25mm f/1.4 and 45mm f/1.8 all give faster, high quality options, and strike me as much more useful for the situations for which these zooms are intended. My own thoughts on zooms like 24-70mm f/2.8, have always struck me as not wide enough, not long enough and not fast enough. When I was shooting weddings, I never used one of these, for either my Canon or Nikon DSLR's, and preferred to use fast primes instead.
Whether Panasonic think that this gives their m4/3 lens range a certain "pro" gravitas, who knows, but I certainly haven't seen a great clamour for lenses like this to be released.
Having said that, for what I do, they could in fact be very useful. 12mm at f2.8 still gives bags of depth of field, and could be very useful for low light location shooting. Plus it would be nice to have a telephoto zoom that doesn't always end up at f/5.6 or f/6.3 at the long end. True a 200mm equivalent isn't that long, but I can see lots of uses for that 2-stop advantage, particularly if the lenses turn in a decent performance wide open.
Whether I'm still using m4/3 when they get released is something I can't really be sure of at the moment, but if I am then I will probably give these a try.