According to Austrian media; yes, they are!
According to some gossips, ORF has already chosen them to present Eurovision Song Contest 2015. But, arguments about adding Conchita Wurst as the third host still goes on. As you remember, Conchita has already told that she wants to be presenter in Green Room.
So, who are Mirjam Weichselbraun & Alice Tumler?
Alice Tumler presents a TV show named “The Big Chance” with Andi Knoll in ORF. And Mirjam Weichselbraun presents a TV show named “Wetten, dass …?” as well.
But unfortunately, there is no official announcement.