Thank You Card Etiquette

I'm very blessed, and when my little "Buhba" was born, I received an OVERWHELMING amount of gifts from friends, family, neighbors, old teachers, etc. - you name it. We received so many gifts that up until the last month or so, we probably only spent $50 or so on clothes for our little guy. How blessed are we!?!? The only downside (if you can call it that) is that I'm a firm believer in the "Thank you" card. I did fairly well and finished about 30 cards two months ago. I sent birth announcements with the cards, and vowed that I'd finish the last 30-40 before Buhba turned six months. Well, in less than two weeks, he'll be seven months old, and they are still not finished. I'm torn because I really want these people to know how grateful that I am for their kindness and for the love and support they showed our family, but it's almost getting to the point of "too little, too late". I don't know what I'd say on the cards at this point: "Dear so-and-so, Remember seven months ago when you gave me the cute little outfit for my baby that he grew out of about five months ago? Well, you may not remember, but thank you. And by the way, here's a birth announcement that looks nothing like my little guy now."? I'm a HUGE "to-do" list writer, and this item is on my daily to-do list, but on top of working two jobs, being a wife and mommy, and trying to sell a house, it just hasn't been crossed out yet - I'm estimating it to be a two day project. I'm very interested to hear other's views about "the thank you card!"