I doubt anyone who is a professional athlete will come out while they are still pursuing a career in sports. There are too many narrow minded people around who will go complaining about sharing showers, or being in close contact with someone who happens to go for people of the same sex.
Which shows a big ego in my opinion, what are the odds a random gay person is into you? If they weren't before coming out, then why would they be afterwards? People who dislike gay people because they simply dislike physical contact with them really think they're too hot/attractive/smexy/...
Just on a side note, I hate it when people start discussing 'rugmunchers' or 'guys who like cock'. Just because a person happens to be gay or bisexual, it doesn't mean all they have on their mind is sex. The only time you say about a straight girl 'she likes teh cock' is when you're saying she's a slut, but are all gay men then by definition sluts? Indubitably, some are, but not all of them XD