There is no information on this available at this time; it depends too heavily on the Vail release schedule (which isn't public), how much it slips as bugs are found, OEM production schedules, etc.
As for actual pricing, probably an OEM Vail unit will be roughly similar in price to a V1 unit today. It's extremely unlikely that there will be
any upgrade pricing in the sense you probably mean; this isn't a home computer, it's more like a network appliance, and there's no retail channel for Windows Home Server software by itself. Some OEMs may choose to offer an upgrade to existing
users of V1 at some cost. Probably this will be accomplished in a fashion similar to the current HP upgrades: you buy a DVD with the new software and do a factory reset with it. But there's no guarantee that any OEM will actually offer this.
I'm not on the WHS team, I just post a lot. :)
