If this keeps up, then in a couple of decades Labour will be the right wing party, the LibDems the left-wing party and the Tories will be struggling to keep from losing status as an parlimentary party.
If social/wedge issues become a larger factor over here that's certainly possible.
I've made this point before, but it's interesting to note that the marginals Labour did best in were generally fairly to very socially conservative and with more religious populations.
Labour did appalling in marginals with largely white collar, socially liberal and more secular populations.
There were a few exceptions, but the generally pattern seems pretty clear.
There was a report a while ago (by Sheffield Uni IIRC) that divided the country into two nations (a familer theme from the '80's although the boundary was slightly different) and it made the point that the "London" area (basically southern england) was "liberal" but largely Conservative voting, while the rest of the country was "conservative" but largely Labour voting. They were overgeneralising quite a bit IMO (East London isn't exactly "liberal" while the South Manchester suburbs aren't exactly socially conservative) but the overall point is pretty sound.
Next few years are probably very important in deciding the political landscape for the next few decades; Labour seem likely to head in an increasingly populist direction (something that's always been possible since the Littleborough & Saddleworth by-election IMO), but exactly what the Tories or LibDems choose to do is kind of uncertain. Both parties seem to be having a lot of internal fighting right now...