This could be to better regulate the move up that's coming....
...when the news hits. We'd be selling to the shorts among others, but the net result would be - or could be - to keep the move upwards steadier, thus preventing DNDN type roller-coaster nuttiness and screwing small fry. It may even make sense, in the same vein, if it's done on Friday too.
It also could be that it sends the message that we are inevitably going up now and no announcement has to be made to start that move up - and that is also a way to moderate or regulate the rise....by not actually making, or by delaying, an announcement near term.
At any rate, it's good to have those shares there to be made available simply to get some control over the stock's movements whenever or whyever it may be needed.
And of course we just saw Prosensa's $80 million and raised them $50 million!! We may be looking to nail down IP that they are now potential buyers of now too......but we'll be richer shortly and they will be back at a disadvantage again on that front. Oh well, they had a week to dream.