If you happen to be familiar with C*-algebras and considering writing an article, here are some suggestions/articles I would like to see:
The representation theorem of Choi-Effros type for operator spaces (due to Ruan?)
Choi-Effros theorem for nuclear maps (stating that a *-homomorphism, from a C*-algebra into a quotient has a completely positive lift if the *-homomorphism is nuclear, in particular when the C*-algebra is nuclear.)
Voiculescu's theorem (stating that if the image a representation of a concrete C*-algebra does not contain any compact operators, then, up to unitary equivalence modulo the compacts, it is absorbed by the identity representation as a direct summand.)
Brown-Douglas-Fillmore theory (classification of essentially normal operators by their essential spectrum and Fredholm index; introduces also K-homology, a homology theory on topological spaces defined using C*-extensions. A special case of KK-theory.)
[[Elliott's theorem]], which says . This is a special case of Kirchberg-Phillips classification for Kirchberg algebras. The latter is spectacular but very technical; it's debatable whether it's advisable to have an article on it. But Elliott's theorem, IMHO, is cute and earthy enough to have an article on.
Aliasing (harmonic analysis). Same comment as above.