This is one of my favorite passages of scripture. What I've often noticed, however, is that we focus on receiving the desires of our heart. But if we look closely at this passage we have to realize that delighting ourselves in the Lord comes first, centering in Him, delighting in Him as the source and the fulfillment of our desires, and then, also, receiving from Him after your life is centered on Him.
Trust in the Lord...Delight in the Lord...Commit your way to the Lord...the center of the passage is Him.
Remember what Yeshua said, "Seek first the Kingdom of God and His righteousness, THEN all of these things shall be added unto you!"
The Lord is the source, the heart, and also ought to be greatest object of our desire. There are lots of good things in this world but we have to be careful about what we want and why. When the Lord is our greatest, our first love, we are delighted in Him, every desire of our hearts will be perfectly fulfilled. That's the promise of this wonderful word. (George, Baht Rivka, Elianna & Obadiah)