Half of those also ban eating pork, but I suspect there's not been an uprise in the Google cafeteria.
How would they feel about working at Google after hearing this? There are two possibilities...
1) Said Orthodox Jew, Muslim, Christian, etc., while privately disapproving of gay marriage, recognizes that his right to be offended ends where my rights begin. Said employee does not wish to shove his own personal brand of "morality" down everyone else's throats by codifying discrimination into the State Constitution, and therefore has no issue with Google's stance on the matter.
Or,
2) Said Orthodox Jew, Muslim, Christian, etc., is upset with his employer because said employee feels he should be entitled to infringe upon the human rights of others. Said employee is free to leave Google, as he is doubtless of little value to the company, or to society in general.
And how would a person who was supporting Prop8 (say, a practicing Orthodox Jew, a Tibetan Buddhist, a Muslim, a Sikh, or a Christian, all faiths which explicitly proscribe homosexual behavior) feel about working at Google after hearing this?