Toys N Bricks reported earlier tonight that ToysRUs.com had the Series 2 Collectible Minifigures up for sale in the US ($1.99 and no limits). An hour later and they were gone. If this isn't a testament as to how difficult it will be to get these figures, I don't know what is.
Your best bets? You can sign up for an e-mail alert at TRU.com if the Series 2 figures go on sale again. It may be that TRU will pulse these out over time. Your only other alternative is to call your local, bricks-and-mortar Toys R Us each day to check on availability. We also don't know what Shop at Home or LEGO Stores have planned, but they will likely have caps on how many you can get per order/trip. Aside from that, there's always BrickLink.
Perhaps if resellers were the ones to buy up all the figures, we might see an influx of supply on BrickLink bringing overall prices down.
(Via Toys N Bricks)