I think that if it's done in a respectful manner and is truly a tribute by another artist, that it's a GREAT thing! I love to hear how other performers recreate Elvis' music. Some keep it traditional, while others try to do their own thing with it! I think that Elvis himself would have loved to hear how others rebirthed his music.
For example, I think Billy Joel did an awesome job on his performances on the "Honeymoon In Vegas" soundtrack!