B737-300 FLT CREW REJECTS THE TKOF DUE TO ACFT TFC ON FINAL AT MSY.

Narrative

AFTER PUSHBACK FROM GATE X; ENG STARTS; AND BEFORE TAXI CHKLIST; THE FO CALLED FOR TAXI. MSY GND CLRED US TO TAXI TO RWY 1 AND ALSO OFFERED RWY 28 WITH AN ACFT ON A 6 MI FINAL (TO DEPART PRIOR TO ARR). WE ACCEPTED CLRNC TO RWY 1 AND I THEN ASKED THE FO TO CHK THE PERFORMANCE FOR RWY 28. HE STATED THE NEW SPDS AND ENG PERFORMANCE. WE WERE ROUNDING THE TERMINAL HEADING E ON TXWY E BTWN TXWYS F AND S WHEN WE STATED THAT WE COULD ACCEPT RWY 28. GND CTL (ALSO WORKING TWR) STATED 'CLRED FOR TKOF RWY 28.' (WE BELIEVE. THERE WAS NO QUESTION BTWN US ON THE CLRNC). 'FLY RWY HDG ROUND THE CORNER AND SWITCH TO TWR.' WE COMPLETED THE BEFORE TKOF CHKLIST; TURNED L ON TXWY S TO RWY 28 AND LEFT THE THRUST LEVERS SLIGHTLY ADVANCED TO KEEP THE ENGS SPOOLED AS TO ACCOMPLISH A ROLLING TKOF AND XFER CTL TO THE FO. WE NOTICED LIGHTS OF AN ACFT ON FINAL AND WERE UNSURE AS THE DISTANCE; BUT THOUGHT IT WAS STILL 5 MI OR SO AWAY. THE ACFT ON FINAL ASKED TWR AS TO OUR INTENTIONS AT WHICH TIME TWR ISSUED GAR INSTRUCTIONS TO ARRIVING ACFT AND CANCELED OUR CLRNC AND CLRED US OFF THE RWY AT THE NEXT TXWY. WE EXITED AT TXWY F (ONE TXWY W OF TXWY S) AND WERE ISSUED INSTRUCTIONS TO TAXI TO RWY 1. WE TAXIED TO RWY 1; CHKED THE FLT ATTENDANTS WERE STILL SECURE; RE-COMPLETED THE CHKLIST AND AN OTHERWISE UNEVENTFUL FLT ENSUED. NOT ALLOWING MYSELF TO BE RUSHED AND DEVIATING FROM THE ORIGINAL PLAN WITH LAST MIN CHANGES. IF A CHANGE TO THE PLAN IS WARRANTED; I NEED TO ENSURE THE BOTH OF US SLOW DOWN. IN HINDSIGHT THERE WAS LITTLE TO NO GAIN FROM DEPARTING RWY 28.