Rosetta is among my favourite names to use in real life. My great-grandmother was named Rosa. Rosetta is a sweet diminutive of that name. After that the link with the Rosetta Stone is great as I love history and many languages.
I think this name is very beautiful and elegant, but then again I love almost all names that are variants of Rose. I think it would be nice for someone to have this name because it is not very popular in the U.S.
The first thing I think of when I hear the name Rosetta is the Rosetta Stone (the important archaeological find, not the language-learning software). That's not a bad association, especially if you like history. The second thing that comes to mind is that ROSETTA is an anagram of TOASTER, but that's not bad either because toasters are useful.
I really like it, and it might be my favorite form of Rose. Also, I think the association with the stone is good, though the language-learning program may be a downside.
I quite like this name, and I don't mind that it has the association with the Egyptian stone. I probably quite like it because of the association with Piper Laurie, whose real birth name is Rosetta Jacobs. :-)