Well, as others have said, not only will Pierce and Pietrus help from a talent perspective, they also provide us with two more perimeter threats, something we're sorely missing right now.
As I said in another post, while Pierce might not solve all problems, I think he solves more than people might think. I think some people are imagining what Pierce would've done if he was in Sasha's position. However, the point is that he wouldn't have been in Sasha's position. With PP out there, defenses would react differently and things would open up for others.
We need him back ASAP.
The one thing I think PP's absence had unquestionably proven is that if this team has any title hopes, it needs to 100% healthy come playoff time.