They'd do that anyway; because they'd want to take advantage of the Graphics and Communications Technologies.
But no, lol, they won't do that because they're constantly watched over Anti-Trust. I think Longhorn will be a breath of fresh air for Microsoft in that its so intercompatable, there is nothing anybody can moan about in it because the Feds have looked over it all the time. They don't want anymore Hundred Million Pound Lawsuits.
I think this will be advantageous for Microsoft in the long run. Because it will make it about the Software and while its likely Linux will still gain for a year or so after Longhorn, in the end it will stop it's cutting into Windows share, because more Closed-Source companies will make better more integrated software for Longhorn for those people who don't like Microsoft but use Windows. Blackcomb I think will start pushing it back.