New leg, no... You could try your luck on a new figure, however Hasbro usually reserves the right to send something, "Of equal value" to you, meaning you could get basically any random figure.
I've actually only gone the route of mailing the item back to Hasbro for a replacement once, and it was a huge mistake. I had picked up the 2006 TSC Vader TIE only to find that the single label was missing. Hasbro (who in the past had sent me a full sticker sheet for my ARC-170 in 2005) refused to send me a single label and instead sent the prepaid mailing label to return it to them for a replacement item. They used the "equal value" caveat, and sure enough, they used it, when two months later I received a 2005 ROTS Obi-Wan JSF on my door. I was able to take it back to Target (where I had gotten the Vader TIE) using the Vader TIE receipt and exchange it for the actual Vader TIE.
It's strange, because back in the Kenner POTF2 days, Hasbro/Kenner was really good about sending replacement parts and labels out. Lately, though, I haven't heard of anyone actually getting the item in question when they've sent it back. More often than not, Hasbro just sends old stock of "equal value" to the item you were trying to get fixed in the first place.
Hence why I didn't even consider biting when they tried to pull the trick on me with the AT-TE and its replacement legs.