1. There is alot of work being done in this space to my knowledge. I know pg has mentioned that there at least a couple YC startups working on this problem and there is already a contingent of sites out there.
There are many different problems in the hiring process and thus opportunity to attack it from many different angles. See some of these:
http://www.simplicant.com/
http://www.iapplicants.com/
http://www.applicantstack.com/
http://www.theresumator.com/ (sexy!)
I've never met anyone that was perfectly content with the way they find and hire people. Not that my experience is huge in this area, but I think there is plenty of room for disruption. And with that comes plenty of room for competition.
2. I've never heard of anything like this, but it sounds like a useful tool. From my anecdotal experience with translators, it seems most of them are in such high demand that they don't need a marketplace (I know 1 in Chinese, 2 in Arabic). Then again, these are full time jobs for the people I know, it might be different for those who work as contractors on shorter projects. The bottom line is that this idea seems like it will require heavy networking effort and may not work out; I'd want to do some market testing really early to test the viability of it.
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If I had to choose between one of these, I'd probably pick #1 and tightly focus on a very specific problem. If you could make an elegant solution for just one piece of the hiring puzzle, you get two outs: a standalone product or a potential acquisition target as this space develops over the coming years. A translation marketplace sounds interesting but building the network/community will be challenging and time-consuming; regardless of your technical solution, you could still fail at creating critical mass. This adds risk of spending much time before you know it will fail; without market validation, I'd be hesitant.
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