Digitimes runs a story about DRAM supplies getting short this year. He mentions Vista SP1 might be a trigger for more DRAM demand:
"Nanya's Pai said that in 2007 major PC OEMs had limited amounts to spend on DRAM because of rising panel and battery prices.
He expects the PC market to have a drop in sales in the first quarter, which will be deeper than the ones in previous years because of strong shipments by PC OEMs to retail channels in the fourth quarter.
But the PC market will rebound in the second quarter, he said. The launch of an updated version of Microsoft Vista on February 15, if its prices do not go up too much compared to its previous version, may help boost DRAM sales, Pai added."
I haven't confirmed this date with Microsoft yet. When I have I will post it.
Microsoft, Windows Vista, Service Pack, SP1, Vista SP1, Release