With double the shares, the price per share is a little more than half what it was last week - it didn't actually go down.

The "little more" is probably because some automated buy programs weren't adjusted in advance and triggered buys when the split went into effect, causing a small rise.

It is very unusual for a stock to be split when it's down. It's usually done when it's been rising, to make the per share price more attractive. Microsoft may have done it for other reasons, but it's easier to push a low cost stock up than a high cost stock, and they really need that stock to go up.

They also announced a (tiny) dividend, which makes it possible for funds that only buy stocks that pay a dividend to buy Microsoft - again, an attempt to get that stock price rising.

Of course, that tiny dividend gets Bill Gates another $100 million a year, tax favored by Shrub's new "economic stimulus package" (translation: "Give more money to the richest Americans package").