For me, this election is REALLY important.. not from the point of view of who is going to govern our country for the next 5 years, but for what it means for the Labour party. Corbyn is going to lose, but he needs to show that Labour can still be a credible opposition. There is a big difference between a worst case scenario of polling 25-26% and being smashed way below 200 seats or managing to rally the traditional Labour core vote, getting 31-32% and beginning to regain a foothold against the SNP in Scotland. I don't think it's too far fetched to say that the first scenario would probably mean the end of Labour as the main opposition party with no realistic expectation for them to be able to return to power within a generation (their path back would be immeasurably more complex than it was in 1983), whereas the latter scenario they would still retain credibility and could possibly hope to mount a serious challenge to return to government in a couple of terms, around 2026-27.
Whatever happens Labour will properly HURT after the the election - FAR more so than in 2015 - in the way that once does when you are on the brink of despair and facing complete ruin, but it's only from these depths that a true soulsearching and reform can take place. People change when their roosters truly come to roost.
As the socialist experiment has demonstrably failed, I fully expect Corbyn to given his marching orders after June 8th to be to eventually be replaced with someone from the moderate wing of the party. It would be extraordinary if he remained as leader after the election. But in many ways he will go down as one of the most important figures in the history of the Labour party because he forced them to the brink of despair which then shaped their future from this point.