Agree, it is only wishful thinking. Also, in similar situations the incumbent Party loses seats (i.e. LBJ and Reagan). I think it is only a question of how many seats are lost in 2006. But, we should be back strong in 2008, assuming we nominate someone with conservative credentials.
I think perhaps if a lot of Dems in otherwise GOP leaning districts manage to win as a fluke this year, they will be vulnerable next time. But it still would be an uphill climb for Repubs to take back control. The Dems of course will fight dirty and do everything they can to keep control another 40 years.
If they win though, at least there are some bright spots. The parties will remain competitive, and presumably the Demo majority would not be that big. This will be a change from that dark period from 1958 to 1994 where the Dems never had fewer than 243 seats. The GOP could hardly come close.
In addition, 12 years in the majority isn't bad. If I'm not mistaken, since the FDR era began the Demo dominance of Congress, up until 1994, the GOP only took control twice in 1946 and 1952. Both those times their majority lasted a mere 2 years. Had the 1994 election been a fluke, and the Dems came back in '96, it would have been a total disaster. But at least now they have improved their standing, created a stronger grass roots organization, and are much better at getting out the vote. So with luck and hard work, even if we are in the minority again in 2007, Repubs are in a better position than they were in previous generations.