I don't think I will. The dx2 has a Tegra chip, which I believe is better than the D3's omap one. Besides, I love the size of the dx2. And as for the front facing cam, I have my tabletfor that, and I've never even used the feature.
I am going to wait until the end of the month and see what happens (if anything) on the X2 GB update front. If nothing changes and I can justify the $ hit, I may seriously consider jumping ship from the X2 to the D3. I see the D3 as a good transitional device (1080p video, FFC, GB, newer Blur) to tide me over until my contract is up next year and the next generation of LTE hardware and coverage is ready.