Well, let's see what kind of Powers/abilities get printed a lot usually:
-Energy acceleration (Typhlosion, Blaziken PK, Feraligatr, Emboar, etc.)
-"revenge damage" or "revenge effects" (Nidoking RR, something in the next set, I believe Krookodile?) (although these usually suck)
-damage prevention (Donphan Prime, Babies, Samurott)
-healing (Nidoqueen RR, Serperior, Blissey Prime)
-card draw (Ninetales, Delcatty PK, Magnezone Prime, many others)
And now that you mention it, last format DID have Gardevoir PL AND Bronzong G as the energy movement guys.
So I wouldn't put it out of the question entirely. Still, Shaymin will stay in the current format for quite some time, so just hold onto them I suppose. ^^