incrediBILL - 7:50 pm on Nov 6, 2012 (gmt 0)

Except Messenger is a tiny little program with a small footprint and little impact on your PC while Skype is a bit bloated pile of... software.

Luckily it appears Skype's IM probably works with programs like Trillian so it won't be a total disaster for those not wanting Skype bloat.