I've really enjoyed my Canon T2i (I think they're on the T4i now). It has great aftermarket firmware and lots of lens options since it's a crop camera, not full-frame. I've shot on my 35mm vintage Zeiss and my 50mm SMC Takumar a ton with great results (using M42 to EOS adapters). You can get a really nice image and great depth-of-field.
The GH2 is really cool, but I personally don't care for the lack of dynamic range, even though I think overall it's a better camera for making films. The GH3 was recently announced, so you might want to hold off and check that out - Philip Bloom made an awesome movie on it here:
http://vimeo.com/49420579
My recommendation is to go on Vimeo and Youtube and just watch a ton of footage from different cameras and see what you like. If you are picky about video quality like I am, then ultimately you need to select a camera that you're going to love. That's why I went with the T2i instead of the GH2 - I just plain liked how the footage looked better, even though the GH2 has an amazing set of features. The T2i looked the same as the 7D's footage to me as well, so I went with the cheaper option and have had no regrets. If you have Netflix, check out the pilot of "Wilfred", which was shot on a 7D.
I don't know how much you are into film, but here are some tips from my own experience:
1. Nail down your workflow, from batteries & shooting to color correction and exporting. The last thing you want to mess around with when you are working on a project is fiddling with every aspect of the tool chain. This also helps you figure out equipment settings and make choices ahead of time. Do you have spare camera batteries? An extra memory card? Video editing software? Color correction? Do you know how to export to the format of your choice and make it look good? Stuff like that.
2. Get a tripod with a fluid head. I use a relatively inexpensive Velbon DV-7000 with a girl's hair scrunchie for smooth pans. This is the first sign of an amateur - shaky footage. Unless you're filming the next Cloverfield, Blair Witch, or Bourne movie, you'll want some sort of stabilization.
3. Audio is 80% of video. Invest in good audio equipment if you are serious about making short films. At minimum, a Zoom H2 on a painter's pole, or with a cheap lav mic like an Audio Technia ATR-35s. Audio is not hard (just put the mic within 12" of the actor's mouth), but most people ignore it, and it's an instant sign of amateur work (along with shaky cam!). I've made some pretty awesome stuff on my iPhone using a good mic and a tripod! haha. If you have a bit of a budget to work with, I would recommend a Sanken COS-11D XLR lav mic (about $480 on B&H, commonly used on films & TV shows), and a Tascam HD-P2 recorder (on sale at B&H right now for $599, probably the cheapest broadcast-spec digital audio recorder available - 192kHz/24-bit). For about $1,200 you can get a really killer audio kit (Sanken lav mic, Tascam recorder, bag, cables, batteries, memory cards). That sounds like a lot, but you get production-quality audio with that. Here's a
quick sample with that setup. If you can capture the vocals on-set, then you can add soundtrack, special effects, foley (footsteps, car engines, etc.) afterwards, and since you have good vocals, everything will match-up & sound real professional.
4. A slider adds a lot to the film. I personally like the
Glidetrack, although you can DIY pretty easily if you are handy.
There's tons of other stuff, but hopefully that helps some - feel free to ask questions, I shoot for-fun films with my buddies all the time and we have a blast :thumbsup: