Dear John looks like it is going to be the B-List version of The Notebook. I like Amanda Seyfried, but other than being nice to look at I just don't see Channing Tatum as a serious actor. When reading this book I envisioned James Franco and Anne Hathaway; I would have been pleased with Franco and Seyfried. Having Tatum be the lead in this does nothing to make me want to see this...I hope I'm wrong and a trailer will convince me otherwise, but right now I'd pass.
If you want to see Tatum show some real potential watch A Guide to Recognizing Your Saints, he's surprisingly effective.
I like that they made a poster for slinky, it shows that he is still in the movie. I wonder how they did his voice. Maybe they had enough voiceover work from Jim Varney that they didn't use in the first two. I hope they didn't recast the role.
On the Dear John front, I don't hate Tatum as much as most, but yes, there are stronger actors that could have been casr
And for Slinky, I've heard conflicting reports, but I think they have a new actor, don't quote me though