I had heard rumblings about this before, but nothing concrete and in print:

http://66.221.11.74/mls/020320garber2.shtml

Specifically,
With football and baseball stadium bills before the legislature and our current budget crunch, I can't see the state helping out. Then again, why would they help baseball and football and not soccer (please don't answer that )?

So does anyone know anything more? I would have to believe that the Thunder are behind this.

In the article they were referring to Blaine and what a great complex it was. Also that they would need to put some type of stadium plan together. This is a big assumption, but from this it looks like any plan would be to ugrade the existing facility at Blaine. To do something like that, they wouldn't need the big funds that are being waved about for the baseball and football. More then likely what ever group that would bring in would foot the bill with possible help from the league. For example AEG already has a group that manages sports facilities.

There was a discussion on BigSoccer a while back about the Twin Cities being an idea expansion location if (let us hope, if nothing else to get rid of the continual whining) the Twins leave.

The first thought was the dome, but it had several down-sides: first, the seat-capacity is too large for the MLS, although the rent is dirt-cheap; the second is the field size (I remember watching the Strikers in the final days of the NASL, but I don't recall the dimension of the field); and third is the playing surface - I would think the Vikings wouldn't mind a change from the run to something like NextTurf, but undoubtedly they'd nix it, instead wanting the half-billion-dollar stadium instead.

The NSC's stadium has a beautiful, international-sized pitch, was designed for expansion, has decent (and expandable) parking, and most soccer fans in Minnesota know of it. The downsides are the location and the track.

The downside for the MLS here in general, is I don't know who would fund a team; as well off as the Thunder consortium is, I don't think they've got enough to fund the losses a MLS team would incur. Actually, the last I heard was that they were pursuing a WUSA team (who's just peachy with the NSC as-is) and running it in conjunction with the Thunder. The budget for WUSA is much more modest, in comparison to the MLS.