Its still legal as a single-copy card in Vintage and Commander, where it continues to wreak havoc in competitive play
There are now different kinds of cards split similar to these, and some of the rules have changed since the original question was asked
With that being said, it does only cost a single white mana to cast, making this a turn 1 all-star and another really strong white token doubler MTG has printed for us
The Role Players Energy is a powerful mechanic, but there are certain cards that any energy deck needs to support its strategy
The final big proliferate-friendly card I'd recommend is Tezzeret the Seeker, which can find your important artifacts more efficiently than the other tutors can, plus it also acts as huge ramp if you've got an Everflowing Chalice or Empowered Autogenerator on the battlefield
go-wide or aggressive decks want fewer and should prefer one-sided wipes