Yes you can Format your texts with bold italics and a strikethrough, to format your text in Google Buzz use the following methods . You can make a text bold by placing a word in between “ * ” , italic by placing a word in between “ _ “ and strikethrough by placing a word in between “– “ , you can also use this In Your Google chats (Gtalk)

Eg,

*Hi this is a bold test*

_Hi this is a italics test_

-Hi this is a strikethrough test-

NB : Don’t put space after the symbols.