Android is hype. Hype drives share prices... sad, but true!
IMHO that can be a good move, but they have to overcome the "slow moving dinosaur" problem. Apple has the "we have the whole range super integrated, from device to desktop to shop and it is super easy" barrier, that both companies will have a hard time to overcome!
Android has the "Open Source is so flexible and everybody can come up with great enhancements" myth to bring to the table.
I understand the share price drop, but maybe their money and business power will produce something useful!