Upload & Sell: Off
I suspect that Adobe will make the beta active until the production version is out, either by releasing a "beta2" or by just extending the expiration date.
That said, depending on a beta (unfinished software) for production work is always a risky proposition. You need to evaluate what pain and suffering you will endure IF there is a gap between beta and production or IF there are gotchas when converting from the beta to production catalog or IF there are any other possible hiccups in the beta software.
Your risk is primarily the LR development time you are investing. Think about how much time that is and the likelihood you will need to come back in the future to make adjustments. Any images that you take to final print/Jpeg/TIFF now will have the adjustments baked-in so the risk for those images may only be any quality tweaks that Adobe makes between now and production.
I'll have to say though that with my limited experimenting to date, quality seems to be on par with LR3 and arguably better in the highlight recovery area.