One of my favourite websites, Politicalbetting.com, was asking this question and gave four possible answers!
1) Lipstick on a pig: a hard-line Conservative government with some Lib Dem detox;
2) An exceptional response to exceptional times, where getting the economy back on track is the sole priority of two right-thinking parties;
3) A true fusion of Lib Dem and Conservative aims to produce something that is better than the sum of the parts; or
4) A left-wing Conservative conspiracy with the Lib Dems against the right wing of the Conservatives?
What do I think? Well I am very tempted by (4) but I couldn't find a suitable image to go with that one so I'll have to settle for he picture below........