i would be against it if he was the chosen to be a sole replacement for another striker.
as a wide man/additional striker to another purchase, i think he could do a decent stand in job, despite his age and pace diminishing he is a very smart and experienced player that rarely wastes the ball and would only add to the experience on and off the pitch in a crucial time when the team needs to retain it's composure.
let's not forget that larsson came from sweden to united and was very effective in a very important time for that team, and it would be ridiculous to suggest that either usa/swedish football is not on a par or that henry was an even better player than larsson in their prime.