Washington has a good amount of talent.
The problem is that he's lazy. I usually go to 1-2 Bengals games per year, and the main thing I noticed at the few games I went to was that every time he finished running his specific route, he was done. He wouldn't budge to help his scrambling QB. He would just stand there. Every single time.
Based on talent alone, he could probably compete for the #2 WR spot in NE, but if he puts in the effort I've always seen from him, he'll be in an uphill battle for the #3-#4 spot and probably will miss out.
He's basically a non-factor on special teams; however, he did put some effort into that this past year and ended up making a couple nice plays on punts.