Till Fellner will be playing four Beethoven sonatas at the Wigmore tomorrow night (the 11th). I'd be there if I were you, and you'd certainly be there if you were me.
Too soon? How about Hilary Hahn at the Barbican on April 1st. She'll be playing music by Ysaÿe, Brahms, Ives, and Bartók. As if that weren't good enough, her accompanist on this go 'round will be the amazing Valentina Lisitsa. Not for the faint of heart.