Guild Wars 2

Once the specizalations come out I understand traits will change, some added some removed and same with utility skills. What I really want is to play my thief the same way, but with a rifle. I love my thief as is but want rifle for world bosses and fear I’m not going to be able to play my d/p thief the same. I do understand yes I can switch back to thief over and over again but just the thought of still wanting to have the specizalation. Think this will be an issue?

Honestly, I’d say it depends mainly on what your usual trait trees are. For example, you mention being D/P. With that in mind, if the specialization removes —say-- Shadow Arts; then you’re going to have a difference in overall playstyle.
(As for myself, I mainly roll with S/P or P/P … so I’m fine as long as I don’t lose CS, Acro, or Trickery to specialize … especially Acro)