Think you'll struggle to find an offer, although most LBS will do a 10% discount when you spend that amount. There may be one or two 09 frames around which may get sold off a bit cheaper. Whilst there is no change to the frames, the RP23 shock has changed with the new boost valve added (worth getting I reckon on the DW). I guess you may see one or two surface 2nd hand too.
Re: sizing, for some reason the medium DW feels a bit smaller than previous mediums, even though the effective top-tube is the same on all 3 @ 23". My HL and my mate's TNT are both mediums, but I went for the large DW, as will my mate when he likely upgrades next year. Turner closed the gap size-wise between med and large, with the large @ 23.6" rather than 24" on previous models.