Yeah, I was also a little disappointed when I heard it. Like,
Estelyn, I much preferred the Dwarvish version of the song. It just feels more grounded and earthy, whereas this is a bit 'light' (I'm not sure exactly how to describe what I mean, but it definitely doesn't suit the Dwarves and their rock and metal worlld.
Of course, it
is called The Hobbit, and I can sort of imagine it as Bilbo's echo of the original Dwarf song and the whole adventure, and then it doesn't seem too out of place. So, while I'm not that keen on it now, I suppose it just depends on its context, both musically and in relation to the film, so I can't really judge it fairly at present.
On another note, if you haven't already, you can also listen to
this track called Radagast the Brown.
edit: So, I've just listened to the credits song a few more times. It still lacks the magnificence of those in the LOTR films, but it has grown on me a bit.