Initially reluctant to endorse protests fully:
http://www.guardian.co.uk/world/2011/jan/18/mohamed-elbaradei-tunisia-egypt
Deciding to return to Egypt some days later:
http://english.aljazeera.net/news/middleeast/2011/01/2011127183223432287.html
In the thick of the protests himself, in fact leading it yesterday:
Egypt’s ElBaradei Has Unfamiliar Role in Protests – NYTimes.com.