There is no moral issue with that, the moral issue comes with what naturally follows that, and where these embryos came from to begin with (but that's beside the point). What I fear is human nature and its lack of "common" sense. Normally I would be willing to give humanity the benefit of the doubt, but not here, not in this age.
This is the only area where I might stand against new technology, where it would logically take the lives of those who are not willing or have no wills of their own in its next steps. If someone made a choice to die and give stem cells, that would be different (and disturbing), but embryos cannot make such a choice.