Well, if the rumour mill is to be believed Sony are going to be going pretty aggressive in the next 18 months or so. In theory........
Jan 2010 - a950 released. Full frame, 32MP, high ISO camera with no video feature. There are lots of arguments about video in the Sony camp at the moment. The general theory is that Sony don't like the current implementation of video on DSLRs and so won't put it in until they are happy.
Jan-April 2010 - A new 600mm lens is rumoured.
April 2010 - Release of the hybrid a1000. Basically a behemoth hybrid thing to try to regain ground lost to Red with sales of Sonys Cinealta cameras falling. An cinema HD video camera also capable of recording 32MP stills without interruption of video. Should cost around the same as the Red systems (so several hundreds of thousands of US$).
a2xx and a3xx series get revamped for April 2010.
a150 release. Very budget DSLR without an inbuilt AF motor.
Sept 2010 - a5xx series updates. Also new a820 - full frame, 32MP with viedo, simplified viewfinder and built in flash. Will have SD slot rather than CF. Expected to be around 1,500US$
At the CES show in 2011 expect the a950.
Also coming soon are the a730 and a750 both of which have been leaked by Sony on their Asia/Pacific support site as they appeared on drop down menus when searching for camera models.
Also expect the "DSC-RX". A mirrorless hybrid "SLR" like the Olympus EP-1 and Panasonic G series. It will have a 14.2MP APS-C sensor. A supposed data sheet can be found
here.
To be honest, in my opinion at least, Sony seem to be "filling in the gaps" in their range rather than much else. Perhaps the a1000 and DSC-RX might change things a little.
In the end though, Sony aren't competing in the pro market. Is this a bad thing? Everyone is always asking "when are Sony going to produce a 1D MK 3/4 or D3/D4 competitor" but I bet if Sony made one very few people would buy it. Most of the Sony sales are at the budget end so a 1D/D3 competitor would only really be a but of window dressing for mere mortals to drool over.
Sony know where the money is and they've grabbed a decent section of the market and only Panasonic (in the compact market) have managed the same thing for a "new" brand.