Is WebOS good for a "software-and-services" company.
There is no doubt that Nokia will alienate their remaining developers ("both of them", as they say) if they would buy Palm. But that isn't important, the question is whether Nokia will be able to sell more devices and more software and services if they would buy Palm for WebOS.
It might be true that WebOS is better for writing third party apps, I have not looked at it. But will it enable Nokia itself to write better software and services? I don't think so. Let us look at the other attempts to create a software economy based upon web apps on mobile.
1) Apple did it in the first year of iPhone OS. Failure, the apps craze happened after Apple released their native SDK and put a proper App Store in iTunes.
2) Nokia and their widsets. Failure. Ovi Store however, which is a kind of App Store, is catching on and making more and more money for participatring developers.
3) Palm and WebOS widgets. Failure. Palm released a native SDK, but after alienating their old developers en not having lots of phones out, going native did not work anymore.
Also, Nokia's first Ovi client was a widset, AFAIK, and it was not very good at all. That means that widgets are not mature enough to write software that can compete with native software.
Conclusion: you cannot write compelling software on a smartphone using widgets. And that is bad news for a software and services company.
There is also of course the in-company wars that will start when Nokia starts using WebOS. Nokia has been gearing up to dump Symbian and start using Linux and Qt for a long time, I don't think it will manage another internal OS war.
The exact OS won't matter much at this time for device sales. That might change if people have spend a lot of cash on software for a certain platform, so they will tend to stay with that platform. And that is good for device sales. Nokia is at a disadvantage here, buying a Nokia does not guarantee that your software will move to the next device you buy from Nokia. Adding another platform (WebOS) to the mix (S40, Symbian, Meego) makes this worse.
What might help is that Nokia replaces it's own widsets with WebOS'es high level layers, putting it on top of Symbian and MeeGo, as a Qt alternative.