They're already at a dead stop. Only people with their heads burried in the ground think there's anything left for Symbian. About the only thing they could do is leverage the N8 and E7 to get everything designed for Qt 4.6 so that MeeGo gets all of Symbian's apps (solving the lack of Google Maps that the N900 currently has, among other things). MeeGo isn't going to launch any time soon, and all the reports suggest that they could get a WP7 N9 out faster than a MeeGo one.
They can drop Symbian completely, for all intents and purposes they drop it on previous devices each time they launch a new one. The S^3 devices are the only ones that aren't like that. Symbian doesn't need the resources, it's only sucking Nokia dry. There's nothing left for it, other than giving it a graceful death before it takes Nokia down entirely.
Devs have already given up on Symbian anyway. Especially with Alien Dalvik I'm pretty sure they'll just say "screw Qt, let's just develop for Android instead and port to MeeGo." That really makes the most sense. If Nokia is lucky, then AD will work for S^3 as well.
Yes, there's an issue with switching gears again, but they have WP7 working well enough to release on the N9 right now, but MeeGo still isn't ready for release. Hell, they released the N900 before it was really ready. There's no point in them sticking along a route if they're not going to get there at all. The N9 should have been released last year. MeeGo should have been out last year. They haven't even officially announced the N9 yet, and it usually takes them 4-8 months to get something out after it has been announced, meaning if lucky we'd get an N9 MeeGo phone in November, but more likely it won't be ready until next year. Sure, keep working on MeeGo, it's good to have their own OS and Ecosystem to build, and within a couple years it could take off with all their other partnerships, but until then, they really need to get something out now.
The biggest strength of Nokia is their hardware. It doesn't matter what OS they run on, I'll still buy them because they make the best phones. A lot of people feel that way as well. Given hardware is what they do well, and everything else is what they **** up, maybe it's best for them to go that direction.