I seem to recall there was a Sheen Supreme color that's quite close - Asian Flower. 'Might need a little patting on and blotting to dupe the texture, though. I really like Sheen Supremes, even though I only have Full Speed and Sheer Mandarin - I wear them often! Full Speed was one of my most worn last year for sure.
Playtime from Quite Cute is definitely a closely related color too - I have a really hard time deciding if I like it better than Pink Popcorn or not, to tell the truth. Pink Popcorn's a little easier to just apply and go.
I didn't back up Pink Popcorn either, but I wouldn't be too concerned - it seems like MAC releases at least one similar color every spring - it certainly is a perfect shade for those early springtime days.
Lastly, it's a bit different color, but if you love the way the texture of Pink Popcorn just melts into the lips and seems almost opalescent, you should definitely check out Venus from Heavenly Creature. It's got the same style to it, but more summery/early fall.