hokay, took me a hot second to figure out what you're saying, but I'm pretty sure I understand and I think I may have an answer for you!

first - the DX2 captures video at 720p @29.97.

I know people just automatically assume that everyone knows what that means, but just incase anyone doesn't, that means it captures video at with a 720 pixel width and 480 pixel height in progressive scan, meaning not-interlaced (like your TV was pre-HD explosion), but like your computer monitor. Supposedly the X2 captures at 29.97 frames per second (not exactly 30, due to fractions of a difference in FPS created by sync-sound), but after checking out the videos I yanked off my droid, the FPS could be all over the place, I'm assuming due to however overloaded your phone was at the time you took the video (slower phone = dropped frames!)

Buuuuuut, in a perfect world, 720p 29.97, 720x480, NTSC progressive YUV (color space, standard).

second - the X2 outputs video as AVC mpeg-4 saved as .3GP with 2 channels of AAC 44.1 kHz audio to the left and right channels. In other words, files pulled off your phone will be mp4's wrapped in 3GP files, no different than the .MP4 file that is standard in iTunes and iPhones. With a little digging, i discovered that the phone streams video to capture at an average 4,000 Kbps VBR (variable bit-rate), compared to the average youtube video, 4,000 is significantly higher.

hooooooowever!
- there is absolutely NO need for you to buy a capture card for your droid! Speaking to you as a film/video editor lol you absolutely do NOT need to purchase one for what you're trying to do! You're computer is perfectly capable of capturing, real time, much larger file formats. Also, I would not recommend down-rezing the picture, MP4's and 3GPs are squashed enough as is, compressing it more would make it a mess.

If I understand what you want to do, correctly, you want to be able to capture what you're doing on the screen of your phone, in real time, to video, while recording yourself explaining what your doing? Like the tutorials you find on Lynda.com? Regardless, I did some digging to see if I could find any free or cheap programs that would enable you to do exactly that, or something close to it, this is what i've come up with:

some software options:
w w w .balesio. c o m /allcapture/eng/features.php
w w w .fraps. c o m

otherwise, you can do it all via VNC connection:
1. download a VNC server app off the market (only one i found that I trusted was droid VNC server BETA) - make sure it's a SERVER not a VIEWER, otherwise you'll end up staring at your desktop on your phone and not the other way around lol
2. on your desktop, download one of the many VNC viewer applications available for free on the web (RealVNC is probably the best in my opinion and offers a free 30 day demo to see if it's something you wanna invest in)

this article outlines it pretty well, i think:
w w w .butterscotch. c o m /tutorial/How-To-Stream-Your-Android-Phone-Screen

I'm currently in the process of setting up the VNC connection to make sure I can route that into VLC or similar to get that real time screen cap you're looking for, so don't trust me just yet on the VNC option lol but as soon as I get a definitive answer I'll let you know