I've actually never been asked about trans status when donating blood. They ask about certain medications, but as testosterone wasn't on the list, I felt confident that it wouldn't matter.
The thing that really bugs me is the male-male sexual contact thing. As many GLBT activist groups have pointed out, it's insanely discriminatory. A male who's in a committed, monogamous relationship with one guy isn't allowed to give blood, whereas a straight guy can go around having random unprotected sex and still donate. They can also have unprotected sex with prostitutes, wait a year, and then donate!
Furthermore, sexually active black women are also disproportionately likely to have HIV, but the Red Cross obviously won't bar them from donating because sexual orientation isn't seen as the same thing as race. They're afraid of racially discriminating (and rightly - they obviously shouldn't bar black women from donating) but not of sexual-orientation discriminating.
Now, if they amended the question to "Have you had unprotected sex with another man..." or "Have you had sex with more than such-and-such a number in the last..." or if they factor in if you've tested negative, then I could understand it. But it's nuts as it is, and they're showing no sign of changing it.
I thought long and hard about lying to the Red Cross, and came to the conclusion that it was for the best. People need blood. I'm healthy and can spare a little blood. I am absolutely sure that I do not have HIV or any other STD. So I'm going to keep lying until they change their policies.