My orchid is going to bloom!

I bought this guy at Wal-Mart — of all unlikely places — last year.  I guess I didn't take care of him very well (temperature, water, bad karma from shopping at Wal-Mart...who knows?), because all his flowers fell off within a week.  So I hacked off the stem, and waited. This summer he grew two leaves, and about a month ago I noticed him sending out new air roots and this new flower stem. 

I don't know what I'm doing right.  He's just sat on my dresser or this southeast window sill.  I kept him watered, but didn't do it regularly, or pay him any special attention.  The balcony garden took up too much of my time. I can't wait to see if he blooms successfully!  The flowers last year were perfectly white.  I'm going to have to rummage around my garden supplies for the stake and clips he came with to keep the blooms upright.