I know it's always the first to get thrown under the bus when these questions are asked but if any of the soaps were to go in the next few years, it'd probably be Hollyoaks. However, I could see something happening like Channel 4 dropping it but it continuing on E4, rather than it being outright axed (like Channel 10 did with Neighbours).
Of the others, they're still among the top rating shows on their channels and there's large investments in them (particularly CS & EE where they've forked out for new outdoor sets in recent years) so I can see them trundling on for another while. The over saturation of the ITV soaps will prove problematic in the long term though. They run the risk of burning themselves out and I'd say this'll be reflected in the ratings at some point. However, until something higher rating and cheaper to make comes along, I'd say we'll have Corrie, Emmerdale & EastEnders for another few years.