In colors that are usually prohibitive to board wipes this will be fantastic. But now the real question, do RUG players go with Maelstrom Wanderer or Riku? I gotta say its still going to be Riku (both will obviously in the deck.) but the idea of loading up on ramp and nothing but 7 cost fatties is really alluring.I really wish they had changed the "non-land card that costs less", this is going to confuse the heck out of newbies who arent familiar with cascade actually refering to CMC, which needless to say is very important for commander.
My issue with Riku is that no sane Magic player ever, EVER let's Riku live if they can help it. But, either way I think the Wanderer will be great in a Riku deck, just as Riku will be great in a Maelstrom Wanderer deck! Animar and Intet actually fit pretty well too... pretty soon you'll be able to just build one big URG deck, with all 4 of the legends, and just swap out generals depending on your mood at the time!
I already have a list for him if you want to see it :)