At the end of SI one a group of heroes appear to have escaped the Skrulls. IIRC Black Bolt and Elektra weren't in that group and they were the onlt two at that point revealed to be Skrulls.

Another thought-just because the Spidey from space turned out to be a Skrull doesn't mean that the other Spidey is not a Skrull. I imagine they could make more than one copy of each hero.

You'll find out about Elektra in an upcoming Avengers book. M Avengers or New Avengers....I forget which one tells a story through the skrulls P.O.V.

Also the Inhumans are getting their own book about the whole Blackbolt thing. I think its titled Secret Invasion: Inhumans or something.

You'll definetly know something this month.