The contract will include the Lough Rd regeneration project, new bridges and roads, offices, and all that other stuff, as well as the new stadium itself. There's no mention of the Highbury redevelopment in the Arsenal.com announcement, so we assume that that site will be handled separately at a later date (which makes sense given that it can't be started till everything else is finished).

McAlpine built the new Hampden Park stadium in Glasgow and the Bobby Moore stand at West Ham's Boleyn Ground. Oh, and the Millennium Dome (if "built" isn't too strong a word).

But not the McAlpine stadium in Huddersfield, which is name after a totally different McAlpine.

Rupe adds...
James Dakin writes with some comments on the Highbury development:

"Arsenal won't be doing the residential development themselves - they will very likely flog the site to a specialist developer. The same goes for the housing at Lough Road and Ashburton/Drayton Park - the Club will sell the right to build that to companies who do that sort of thing for a living."

"There has been misreporting in the press about the cost of the stadium. They have added up the cost of the works mentioned in today's announcement and the various residential projects and reached numbers of approx £400m."

"In fact so far as the club is concerned they should have subtracted a big number for the residential developments since this is in fact cash coming to the club from the companies that will acquire the sites from the club. The residential developers then have to fund the developments themselves which has nothing to do with the club. (There are possible variations on this eg the club shares development profits with the developers etc.)"