Quote from bradleyjxYes. You can use any promo as long as the card itself has been printed in a standard-legal set.
Keep in mind, though, that foil promos fall under the same disclaimer as normal foils: your foils can't be distinguishable from non-foils when the deck's just on the table.
Quote from Commander GrevenI'm going on record right now and stating that before the end of 2012 we will see foil dual lands in booster packs (The real, Alpha dual lands). You can quote me on that.