Good points everyone, especially Policywonk with cbeebies style explanation of PR .
Onebat - that is a worrying scenario.
I think Clegg has definitely gone to the Tories first as the only possibly way of not alienating the right wing electorate. He is playing it canny and he does have a very democratic and principled party behind him.
This is also make or break for the Tories, I think this is the beginning of the end for them. It may not happen right now but they must know that Things Have Changed. (Which is why Murdoch, et al will play very dirty).
I think this is going to end up being not just about parliament but also about all those who woo the Tories - they will do everything they can to stop their party being relegated to history.
Minority Tory government increasingly looking like a pretty good outcome (as long as they don't get a majority next time).
As Policywonk says the public may not be ready for a Lib/Lab coalition brought together to bring about electoral reform. Also Gordon's relative unpopularity may play a role here (much as I like and respect him).
Also we need Labour to be seen as very very solid with no infighting, etc (bit of a loose cannon this I fear, although Tories have the same concern).