No idea whether Castro's bowing out of official power will make any difference in modern Cuba. After all, his brother and likely successor has been technically in charge for over a year now. Still, at least one half of Bostodelphia is always interested in an occasion for a celebratory beverage, so we'll recommend the Cuba Libre.
Rum drinks aren't the cheesesteak's specialty, but the Cuba Libre is easy, and easy on the palette to those who don't have the Impaler's stronger tastes. Basically we're just talking about a rum and coke with lime.
1 1/2-2 oz. rum, any kind.
up to 2 oz. lime juice
Half fill a highball or collins glass with ice, add lime juice, rum, fill remainder of glass with cola, and garnish with lime.
Now I know at least one cola bottler is making their coke with lime flavor. I won't recommend that shortcut, but I wouldn't stop you. In fact, I'd be curious how it goes. I also prefer fresh lime juice to the Rosie's stuff, which is really lime juice and sugar syrup. I'm ok with Rosie's in Margaritas and the like, but if the juice is being added to a sugary soda, I think you may be overdoing it.
Now according to Salvatore Calabrese, the Cuba Libre's creation coincided with the creation of Coca-Cola and the presence of U.S. troops in Cuba. His recipe then insists on white Bacardi rum and Coca-Cola. My other bartending manual, which I treat as more authoritative simply because it's more battered, isn't as specific and I'll follow its lead. On hand I only have a bottle of Bacardi and a bottle of Sailor Jerry. While historically of the Island, Bacardi's wikipedia entry casts them very much as a "rum maker in exile," so is probably the more appropriate. Who knows, maybe I'll mix both. Any case, my more trusted book says your rum's up to you.
Again, while your cola should "technically" be Coca Cola, there are so many smaller bottlers out there doing interesting, and corn syrup and caffeine free things with cola. Boylan's Natural Cane Cola is what I'd recommend if you can find it. For tonight, I found two bottles of cricket green tea cola in the refrigerator case of Potbelly Sandwich Works. Just had one bottle on it's lonesome: good, light, refreshing taste that stayed with you without any caffeine buzz or bite. Should make a good mix with the rum and lime flavors.
On the lime, besides my Rosie's ban, lately, I've been using a whole juiced lime in my drinks and have got nothing but praise. Could be the time of year has everyone craving a little more citrus, or simply the fact that limes in Philadelphia in winter just aren't as juicy as they would be other times of year. Whatever the case, while I'm more careful with more subtly balanced drinks, when a drink has called for more than an ounce of lime this time of year, I just juice the whole lime and add it to the drink, scooping the pulp into the shaker if it's a shaker drink. In this case, I think I'll let the juice, spirit, and cola stand without the pulp, though some of my recipes suggest tossing your rind into the glass as well.
(Incidentally, one of my "bartender's card decks" suggest just club soda for the libre. That would certainly make for a lighter, less sweet drink, but I don't know how the card deck's manufacturer got the cola brown color for its illustration.).
update: Coddy grills up a food pairing that completely slipped my mind.