Well, if you're in desperate search for a starter, then Smeargle is up there with the likes of Jirachi. Not as all-purpose as Sableye, but having enough tricks like the Jirachis to merit its place as a starter. Getting a quick peek at your opponent's hand isn't a bad thing either. It also helps the SP Matchup for rush decks more then one would imagine.
For example, you have any given SP deck vs. Kingdra. Kingdra has a Smeargle and a Horsea benched, SP has started the game with a Call energy and has its 3 SP's on the field. The Kingdra player uses Portrait. Now at this point, it is NOT very likely that the SP player will have 2 Spray in hand. So let's assume they have one Spray. And a Collector. They would know that if they let Smeargle grab the Collector, the Kingdra player can get double Uxie to dance around the spray. Furthermore, Smeargle also reveals vital information about the hand of the SP player - should they not play the Spray, then Kingdra KNOWS its there and thus will play around it. So SP likely sprays the Smeargle. And at that point, Kingdra would be "Alright, Collector..." and the game starts rolling.
Bit of a drawn out example but it's how I've been using it so far. Funky little card really.