Looks like Air Deccan is adding more flights to connect Bangalore and Trichy. The schedule from Trichy to Bangalore / Chennai is as follows.

DN-174 Bangalore ATR 7:50 9:00 Daily 30th Mar 2008
DN-176 Bangalore ATR 22:10 23:25 Daily 4th May 2008
DN-154 Chennai ATR 11:35 12:45 Daily 30th Mar 2008
 DN-164 Chennai ATR 22:05 23:15 Daily 4th May 2008

The schedules (in Red) is not approved yet. But this new schedule will be great for those who fly into Bangalore from outside the country and don’t have to wait well into the day to get to Trichy.