Recently, a bunch of new DSLRs come out with Live View functionality - including EOS 1D3, 40D, Nikon D3, D300, Sony A700 etc. These cameras use sensors that have an electronic shutter mechanism in the circuit for "live view", so that individual frames can be obtained with the physical shutter open all the time.
The question is, will such a design make higher sync speeds possible?
It was the case with 1D, D70, D50, D40 (all of which use combined electronic/mechanical shutter), whose sync speed was rated 1/500s and in practice it goes way beyond that stated limit.
Hardware aside, there is another question of whether to make use of the electronic shutter in still image capture - which is a decision by the camera designer. Traditionally, the X-sync speed is determined by the physical shutter and beyond X-sync speed, the 2nd curtain starts to move before the 1st curtain fully opens - if this design is still used in DSLRs, the electronic shutter cannot be used for still image capture. However, if the design is such that for exposures faster than X-sync, the physical shutter operates at X-sync, then the electronic shutter can be used.
So the question becomes: is it beneficial to keep the old shutter operation design when electronic shutter is available?
(The benefit of higher X-sync is simply higher possible flash-ambient ratio, which can be handy in many applications. )