There's really nothing much to say that hasn't been said 1,000 times over in the comments sections of various blog posts and articles at the Washington Post's website, or over in the DC and MLS forums at B*gSawker, but I'll sum it up for you guys (executive summary? it's all Montreal's fault
):
1) The team worked with the District for close to a decade to get something done.
2) Once they settled on the Poplar Point site, the team spent millions lobbying Congress to transfer the land to the District for a mixed-use development, anchored by a soccer stadium.
3) After the land transfer, the team worked out a deal with the District whereby the team's new owners, who are developers specializing in mixed-use urban infill projects, would pay for the stadium in exchange for the right to develop the rest of the property.
4) While this was happening, MLB decided to move the Expos, and in the process of "negotiating" with the District, decided to save money on Vaseline and just shove it to the District raw and hard. Voters were not amused. The Nationals didn't even bother paying rent their first year in the new stadium, claiming it wasn't usable, despite, well, using it. Voters were even less amused.
5) A new mayor took over and, along with the Council, took a "stand" against team owners looking for a "handout" and sank the Poplar Point deal, instead putting it out for competetive bidding.
6) The team owners decided not to bid on the project, but didn't rule out working with the District if the project included a stadium.
7) After a long bidding process, the winning bid included a soccer stadium.
8) Financial armageddon strikes.
9) The developer who submitted the winning bid pulls out of the project.
10) The team, at this point desperate for a new stadium in order to secure their long-term viability in the DC market, strikes a deal with PG County to work towards building a stadium as part of a mixed-use development near a Metro station. The likely sites are approximately seven miles away from RFK stadium.
11) The District is left with no development, no soccer team, and the upkeep costs for a big chunk of what used to be federal land. Yeah, that's my hometown for you.
12) Some United supporters from Virginia get their panties in a bunch because the new stadium will be sooooooooo much further away from them.
13) DC and MD residents mock said Virginia supporters, call them pussies, snobs, etc.
14) Most United supporters are saddened, but not surprised that the situation came to this, and just hope that the stadium does indeed end up near a Metro station, and that it doesn't look exactly like Toyota Park, or the Philly stadium, or Pizza Hut Park, or the Big Dick, or...you get the idea.
To sum up: MLB are a bunch of greedy bastards who ruined everything, people from VA and MD don't really like each other (to be fair, they *DID* fight a rather bloody war once), and most supporters are just looking for closure.