Nope, no continental teams in WT events. ProContinental teams, yes (hence Team Type 1 and United Healthcare can show up if invited), but not Continental.
As to WT status possibly attracting something better from teams like Euskaltel and Ag2r? Well, just look at the teams they send to races like the Tour Down Under. Theoretically it could lead to better teams from them because of points being available. But there's not enough time for the big guns to do it then be back for the Vuelta, and the Vuelta a Burgos is just before it. All Euskaltel's big guns will be there. Ag2r? Well, there's the Tour de l'Ain, the Tour de Limousin, the Tour Poitou-Charentes et de la Vienne and the GP Ouest France-Plouay. Quite a lot of French calendar races there. Quite likely you'll get a makeshift team and even if you do get the better riders on the teams, they'll just roll round to make the numbers up like Andy Schleck at Tirreno-Adriatico, in which case if you have enough 'name' riders anyway (as they will have in Colorado and Utah with Radioshack, BMC, HTC, Rabo etc rocking into town) you may as well save the money that the WT costs and have those continental teams. After all, it's the peak of their season. They want that race more than Euskaltel or Ag2r ever will.