It'll be harder for them to get their bills through parliament, so it's quite an important change really. It's one of the reasons I like Corbyn as Labour leader - with him I'm reassured that Labour will vote against NHS dismantling, for example, whereas a Blairite Labour, even if it had more seats, would be more likely to vote along with the Cons. Also LibDems will be more likely to lean left now they see it's popular and some Tories will sway slightly less to the right. There have always been a few Tory rebels who vote against them sometimes and they'll feel empowered now.
It's not world changing, but it is an improvement.