OK, they have it at Krogers now.  I just tried it and here's the skinny:
I hate those gross fruity drinks out today (Strawberry/kiwi, blue raspberry, watermelon....yuck...), so I wasn't expecting much of Pepsi Blue.  It wasn't too bad!  It's not as sweet as it looks (in fact, I'd say it's less sweet than regular Pepsi), and it has a head on it like root beer when you pour it into a glass.  It has a light berry/cola taste that seems to be just about right, but it's super carbonated, so prepare to burp 

 .  I'd buy it again!
[gene shalot] Pepsi Blue....it BLUE me away!  I sure wasn't feeling the BLUES after drinking this stuff.  One taste, and my taste buds went ka-BLUE-ee!  When people heard that Pepsi was making a blue drink, they thought they BLUE it.  It turns out, they now just BLUE past the competition!...[/gene shallot]