I got an email saying thank you for shopping small so maybe a statement credit is on the way 
I'm also waiting for mine. I made two purchases today with two different Amex cards. Earlier this week I received the confirmation emails that my cards were successfully registered, and the merchants are in their ShopSmall database, so I fully expect to receive the credits. I purchased some items from a family owned local gift shop that specializes in Scandinavian imports, and we bought our tree from a family owned Christmas tree lot. We participated in Small Business Saturday last year and purchased from the same tree lot and received the credit. Anyway, I keep checking my email; I'm hoping to get confirmation soon.
Current Scores: EQ 775 (03/04/2014), EX 756 (03/01/2014), TU 760 (03/01/2014)
Ruby Spade Garden Club Member - Last App: 03/04/2013 - No apps until 2014
Cards: Cap1 Venture 6.4k, Cap1 Quicksilver MC 1.75k, BankAmericard 1-2-3 Visa Signature - UCF Alumni Association 5k, Discover 7k, Citi Diamond Preferred MC 10.35k, Wells Fargo Rewards Visa 7k, Chase Freedom 5k, Chase Ink 7.5k, Amex Green NPSL, Dillard's Amex 7.5k, JC Penney 7.5k, Kay Jeweler's 5.1k
I just got 2 of my confirmation emails- expecting 2 more. Registered 4 cards this year. Be on the look out- the emails seem to be on their way.
Starting Score: 642
Too late for me, maybe next year.
I registered 6 cards (I have 4 accounts, and wife is AU on 2 cards) total. I actually used 5 of them today for between $25 - $30. I have done a similar promo with Amex a few months ago (can't remember what it was) that resulted in a $20 credit per card for small businesses in certain cities, and I did it with 3 cards at the time for $60. I was credited within a week or so - I wouldn't be too worried about them following through on the account credits.
I recall receiving an email once the charge posted, which takes 1+ days. And keep in mind that weekend charges sometimes get batched up with Monday's transactions depending on the merchant, so could be towards the middle of the week that we see some confirmation of the credits.
I was able to use 5 out of the 6 cards today towards the promo - it's harder than it sounds to find a small biz that you want to spend $25+ at. As long as there's no hiccups (which I don't expect), it was a cool $125 free today! I'll never forget my kids' faces when I told them "no, that toy isn't expensive enough... get the other one" lol 
I just feel bad that I couldn't take advantage of the 6th card, as the pastry shop we were going to was too far and our kids were ready to go home. Hopefully next year we can plan it out better!