They will need to get the samples cleared before releasing the song and not getting a law suit involved.
Stuntmasterz got to #10 in the UK with The Ladyboy Is Mine so they must've had the sample cleared to release their mash up as an official single. However, I suspect getting the Destiny's Child sample cleared would be a bit trickier.
Would be cool if both samples were cleared as it is a brilliant dance anthem in waiting. Getting a session singer to sing Beyonce's vocals would cheapen the song imo, and from what I've read elsewhere Beyonce apparently really likes what they've done so who knows.