I plan on keeping mine forever. I got mine with the intention of having eggs and they ended up being more like pets. (heck they are barely laying right now due to molting & "winter"{hardly can be called a winter here in central Tx})
I don't eat meat & neither does DH so we don't have any reason to slaughter them, and considering we're pretty attached to them I don't think I could ever let someone else eat them. I've got plenty of coop space & all the birds free range all day everyday so I'm not too worried about running out of room. With them free ranging it doesn't cost much to feed them. I guess now all I have to do is hold off on getting any more for the next couple years while these mature and do their thing, I have some that aren't even at POL yet!