When reading On Lackadaisical Development over at Tam's Palm, I stumbled a bit on the phrase "There is a distinct lack of commitment and dedication in comparison to closed source and commercial applications." in the first paragraph. This is only true if the author is short on time, and thinks his product is quite finished as-is. The same goes for a commercial product, where the development team is just directed to another [new] project that'll bring in money if the product is thought mature. Of course, if people offer money for implementing $feature, the company is glad to put a developer on it, if it's going to make more profit that way. That's generally the key: more features so the people keep buying.
Also, an Open Source author is generally quite enthousiastic about his product, so he'll try to make it as good as possible: clean code, low on bugs etc. Features cost extra time and aren't always that trivial to implement and maintain. A company thinks in features: that's what sells them products. Their number should be high enough to weigh against the general quality of the product.
My point is: look at Agendus, for example. For the last few major versions, only features have been added, as that's what sells. It's getting bigger and slower by the version, still causing crashes and other problems, as a glance at their support form reaffirms. I've stopped tracking it a few versions ago. However, I considered getting the source, stripping out all unneeded features and debugging it. However, that's of course not possible with a commercial, closed source product. With an Open Source program, anyone can step in and help out with implementing features, fixing bugs, or can even fork the whole program [a process which isn't to be taken too lightly BTW] and build on that. Of course, the original author or whoever is maintaining it will have to approve [some can be quite protective over their child], but if their main issue is a shortage of time and interest, they'll be glad anyone is wanting to help out.
So, the difference in commitment to an Open Source project depends on how much time the author has and whether his interest didn't shift away to other things. However, anyone can help him out. The amount of commitment of a company to a project is how much money it makes for them. If it doesn't generate enough anymore, they'll add some features. If people start screaming too loudly, they fix some bugs. Implementing features and coding in general costs them money, so they'll only do so if they expect a nice revenue. OSS programmers do it out of a certain passion for their program, which tends to result in better programs [if they reach maturity, that is; but then, quite some commercial software doesn't seem to reach that either].
There, now that's from my heart, I can go back to writing at my paper :)