While Mahe's primary role is as the Eagles kickoff and punt returner, he's been a nice player to fit into the backfield when necessary. That role could increase, depending on how the Eagles handle Correll Buckhalter's impending free agency. The Eagles are going to do all they can to keep Buckhalter, but if he does leave, the Eagles will be more likely to step up their efforts keep Mahe in town.
Mahe has made himself valuable enough that other teams will have an interest in him if he hits free agency. The Eagles value him as well and will work to keep him on their roster.
The bottom line: While Mahe is likely to attract some attention, he's likely to remain an Eagle. Other teams will be interested, but aren't likely to throw huge amounts of money at Mahe to jump ship. Instead, he's likely to get a nice raise to stay with the Eagles and return to his usual role as a return man and occasional running back.