You know, I always liked the "draw a card at the beginning of the next turn's upkeep" thing that a lot of old cards had. For Instants and Sorceries, it kept your hand topped up during your opponent's turn, and for permanents, it was just a nice bonus. That's one of the reasons I like this card. The other reason is because it effectively doubles up some mana. This can very useful in a lot of situations. Probably the best example is being used in blue counter deck. Let's say your opponent plays something that you have to counter (let's say Apocalypse) but you only have 1 blue mana available and a Counterspell in your hand. Well, with this card, you know have the mana and a replacement card at the beginning of the next turn! There are some downfalls to this card though. If you need 2 colours of mana, you're out of luck. Also, it does cost 3 mana to put down, so it's not the fastest or cheapest solution to a mana shortage.
Pros: Produces 2 mana for 1, draws you a card
Cons: A little expensive, only produces 1 colour