My 160Gb drive took considerably longer than an hour to index. Maybe more like, uh, 12 or so? I've got about 24Gb free...
It DID seem like it would be done indexing after shorter stretches of time after installing, but then I'd get hideously anemic result sets for any of my searches. I finally left my system on all night (I disabled sleeping) and the next day Spotlight worked like a charm.