According to an interview with Arnold a couple months back, the original will be out this year. If you do a search on the forum, I believe there's a thread about it.
As for why they're releasing part 2 first, I assume they're being released by different companies, and Central Park Media (releasing part 2) decided to release it now, while whatever company will be doing the original is not releasing it yet, unless CPM knows that the original will be released around the same time, and that's why they're releasing it. I don't know.