Hum-Tum is cute and funny. Nice for some light hearted entertainment. Both Rani and Saif has become seasoned actors and are a treat to watch :). One disheartening factor was that ultimately this movie also turned out to be a copy of "Harry met Sally" which I have not seen yet and so I enjoyed Hum-Tum. However it is sad that even all the good Hindi Movies turn out to be inspired from some foreign movie.
For the record: (Not personally verified since I have not seen the English ones)
Ghulam: On the Water Front
Munna Bhai MBBS: Patch Adams
Hum Tum: Harry Met Sally
Mohabbaten: Dead Poet's Society (my loathing for Mohabbatein increased quite a lot after watching the original English one)
even paap, the debut movie of Pooja Bhatt the director draws inspiration from many movies including "the witness" among others.