The finale of season one will be on May 13 2010, which will be the 22nd and last episode. Most likly they'll take a break to film più The Vampire Diaries episodes so they should be done da September, and I say that because season one started in September!
The reason they took the breaks is too film più episodes. It's still season one untill May 13! If te want to confermare this o get the summary of any episodes te may cheak her on WikiPedia!
link I got all my information from there, so I own none of what I detto except for my words, the ideas came from here and I beleive them! All except the September starting of season two, that WAS mine!