If Andy gets a Slam he'll probs get an OBE.
Henman got one near the end of his career without winning Slam, so I reckon Andy should too even if he never wins one. Look at his titles to date - 21 compared to Henman's 11 in his entire career, and only one of those was a Masters - and Andy, provided he keeps fit, has a good 5 or 6 years left.