As atrios notes here, Sen. H. Reid looks like he's planning to fold again in the face of stiff opposition. On the merits of seating Burris I'm a bit agnostic. On strictly legal grounds there is a case for denying him the seat and a case for the idea that such a denial would be improper (see here for a general discussion).
But on the political front, this shows just what a weak player Harry Reid is. In poker terms, Harry Reid is a WAG: Weak AGressive. In terms of poker typology, this is basically the type of player that is actively looking to give their chips away. Aggressive players generally raise with inferior holdings, always bet draws, and tend to bluff at any unraised pot post flop. They want to put their money in the middle. Weak players tend to fold when they should not if pressure is applied. They will fold straight and flush draws even when they have the pot odds to call, they will raise then fold with top pair, and generally rarely call any all in unless they have the nuts (the best possible hand). In other words, WAGs are the worst of both worlds. They aggressively build up the stakes, but then fail to fight for them by following through.
But back to Reid: politically he's a WAG. Time and time again, he will talk tough, generating press and hyping expectations of a showdown, only to fold to pressure when the other side is willing to commit to a fight. Harry Reid did a great job of leading the Minority, several times out maneuvering the inept Bill Frist with parliamentary procedure, but as a majority leader he's been weak. He needs to learn to either fight or shut his damn mouth if he ain't going to.