While it's interesting to see Labour going closer to their roots, they're simply not going to be electable. While Corbyn does have some good points, for example the previously mentioned attitude towards refugees, there's too many toxic issues with him. Admittedly some are overblown by the media, but his attitude to the Falklands will fuck him over when it comes to public opinion for example.
I only hope that the Lib Dems take this opportunity to rebuild themselves and become credible. They're unlikely to overtake Labour but they could certainly take votes from the Tories. Labour could have done much better than they did before if only they came up with a credible alternative to austerity. They couldn't. Their plan was basically 'We're not the Tories'. I mean, it's a nice plan but it has less substance than David Cameron.