Here's my take one what to do with some of the current WWE roster who seem to be... not doing anything:

Tyson Kidd & Evan Bourne
Pair up Evan Bourne & Tyson Kidd as a heel tag team when Evan returns, managed by Paul Heyman. Have them start a rivalry with Sin Cara and Rey Mysterio Jr which ultimately has the two teams facing each other for the tag titles at WM.
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To the point, here is my suggestion for the main event at WM:

Rock and Cena versus CM Punk and Stone Cold
Punk and Stone Cold win, but Undertaker shows up. He knocks out CM Punk post match and celebrates with Stone Cold -- and all the legends applaud The Undertaker's official retirement

How Cena and Rock team up: Cena helps Rock after getting jumped by Punk at an earlier ...