With the completion of the first human genomes on "sequencing chips", Human genome sequencing costs are dropping rapidly, as is the speed to complete the analysis.
At the same time significant progress is being made in the ability to isolate fetal cells from maternal blood, and the ability to sequence from smaller and smaller samples.
Jonathan M Rothberg is negotiating the terms of a bet about this prediction. It will soon be added to Bets on the Record.
Submission to genbank of the sequence from the fetal genome. At least 6 fold coverage of the haploid genome - 18 billion mapped bases. >95% coverage of non-repetitive sequence. If challenger required publication in a peer reviewed journal, then the date would be date of submission to genbank, confirmation by publication can take additional time.