If you want to tempt a friend who used to play World of Warcraft back into the fold, the revamped Scroll of Resurrection should do just the trick. Should your friend accept the invite, they'll get a free server switch to your realm and faction, seven days of game time, a free upgrade to Cataclysm and the choice to instantly level up one of their characters to 80. Yikes.
Blizzard announced the limited offer on Battle.Net . If your friend accepts the invite and buys a month of game time you'll get a Spectral Gryphon (Alliance) or a Spectral Wind Rider (Horde) for free. To be eligible, the invitee must have bought a month of WoW game time at some point, and must have an account that's been inactive since Sunday. That means you won't be able to un-sub and res-ub to get access to the benefits. Alas.
Those are some pretty tempting rewards for the returning player, though the sudden jump from low levels to a fully kitted out level 80 toon could be quite bewildering. It'll drop your friend right at the start of Cataclysm, though, so they'll have plenty to explore during their free week, and perhaps beyond. Are you tempted?