I bought a Fluid type trainer from MEC last winter. Used it during the shitty months fairly often on my xc hardtail with a slick on the back. Guess what, on my first spring ride I almost puked and died. The trainer IMO just doesn't work you like climbing off-road does. It doesn't work the right muscles or something. Plus it's boring as hell and unlike biking where the wind blows the sweat off of you, you just gush sweat everywhere with no offsetting joy of wind, momentum that biking normally gives you.
You weren't trying hard enough. Spinning the trainer at 60% of your max for an hour does nothing except make you very sweaty. Get a heart rate monitor, fill the ipod with lots of fast tunes and once you've given yourself a good warm-up, pin it. If you're doing it right, you should be absolutely cooked after 30-45 minutes. Spin at near zero resistance for another 10 minutes to cool down. Don't do this everyday or you'll injure yourself.
Of course a more structured workout is very helpful. Especially to help with the boredom. There are probably lots of resources on the web for this type of thing. I do intervals of varying lengths.
And no, a trainer workout is nothing like riding outside, but when the ground is covered in snow or you're recovering from a broken vertebrae it is much better than sitting on the couch.