You took your time getting to 80. Rather than getting wow gold a "you snooze, you lose" attitude, your raid leader looked at options of getting you in and suggested DPS. You said you'd give it a go, but didn't like it. So now he's seeing if someone else wants to go DPS.
Sounds to me like your raid group looks out for one another. As long as you don't drop the ball and work to do well as a healer as you had in the past, I don't see the problem here. Be glad you have such an awesome raid group and enjoy playing the game!
To answer Sars and others, the kind of raid leader who asks a healer to dps is one who has too many healers. A rare problem but one that does happen sometimes.
I agree with Evol on this one. The raid leader is trying to accomodate multiple people.
It is not selfish to want to go back to healing. But if the RL comes back to wow gold you and says, "no one else wants to go DPS either. Since you only want to heal, I don't have a spot for you at this time," it may then become selfish if you threw a fit about it not having a spot.
At the start of Wrath my guild was focused on 10 man content. In ten man content you have 2 healers. When we raided I had my two "best" healers heal and offered the other healers to do the respec dance and have a shot at coming as DPS.
Yeah their DPS was lower than a "real" dps (mostly due to their inexperience or gear with no hit rating on it) but it was acceptable and they managed to get healing gear.
If you "took your time" getting to 80 while your raid was wiping to content but they still wanna bring you in to get gear you should be happy. As your gear improves and you learn the fights reopen the wow gold issue with your raid leader and let them know you really appreciate being taken as DPS but you'd love the opportunity to heal.