The small assortment of characters sort of reminds me of a typical Palisades Toys series, only all the characters are "big guns".
As much as I'm hoping they eventually make Walter and Uncle Deadley, it won't surprise me if they eventually release Miss Piggy, Gonzo, and maybe Rowlf, Scooter, and Bunsen before either.
It sort of amazes me that there has been so much Beaker merchandise without Bunsen being included as well (though there has been a bit of Bunsen merchandise). I would think their popularity is equal. Beaker may be a more fun character, but I'd think it'd be better to have a Bunsen with Beaker (I remember when I first bougth the Bunsen action figure, the Muppet Labs playset wasn't out yet so I had to play with Bunsen without Beaker for a few weeks). Though they are a duo where it's not weird whenever only one appears without the other.