Wow, I find this a very surprising thread. I loved torchlight. I think anyone who is disappointed is just expecting it to be something it never tried to be.
The art - I thought was great. The style stays the same from zone to zone, but the palette differs drastically, keeping it fresh. Compare to D2, where every Act has the same muted tones, which create a spooky ambiance, but also jade you to the difference between acts. D2 all felt the same. As for cartoony... yes, but with style. This was a much much smaller project than Diablo... it was created to be a game, not an epic, and for that I think the graphics are great.
The skills - I had great fun with two Destroyer builds. Besides the micro-managing buffs, each had a couple skills to use on mobs of enemies and another couple for big guys. The pace and scenery changes keep that fresh for quite some time. If it does get old to you, I think you're just looking for a bigger game. The Summoner Alchemist was also fun, and was a class heavily built on spells, as opposed to class skills, another well incorporated idea.
Mods - you can't blame the game for a lack of mods. The fact that they made it so easy, and even gave us a modding program speaks so much. Compare to D3...
Pet AI was horrible.
So, Torchlight could have been more, but for the scope of game they tried to make, it is perfect.
Pretty much agree. It wasn't super replayable but for what it is, and for what it cost - it was a pretty good hack 'n' slash. I'm excited for number 2.