The irexshop gives a table summarizing the differences between the DR1000 and the DR1000S.
https://www.irexshop.com/product_inf...products_id=69
There is on the iRex Blog a sign up for the DR1000SW:
http://i-to-i.irexnet.com/2009/02/13...reader-1000sw/
sounds like an "any day now..." sort of thing (for non-US readers, that's a slang phrase meaning might happen, might not happen).
Seems unlikely they'd issue a DR1000SW model, with the current DR1000S power problems not yet coded around, but stranger things have happened.