there is a site where will calculate the result if predict votes.
my prediction had the lib dems been slaughtered down to 16 seats and labour 15 short of a power. so probably would have led to a lab lib coalition. Labour are easily more popular than they were when lost the election in england and dont need much of a swing to get ahead of the tories again in seats, remember lab need less votes per seat than the tories.
http://ukpollingreport.co.uk/swing-calculator
What happened in scotland is an event but those votes werent lost to the tories or lib dems which is very relevant.
Ironically I had the tories on a higher share of the national vote but with less seats, if that result came about in real life I think the media would make a big issue of a labour government been in power with less votes than the tories and PR would be raised again as it wouldnt be seen as democratic.