yeah possibility of it is open. he may make changes.

the Union budget 2012-13, as you know is presented not 28feb but on march 16 because of polls in 5 states.

as of now Loksabha is in recess, it means no proceeding will take place. only after recess, members of Parliament will involve in debate, after passing, it will go ti President for assent.

I am not sure but Parliament will resume, somewhere in 4th week of april, so we could expect budget will pass in may.