I too think that landing is the correct decision.
I would however be in (slightly) less of a hurry then to evacuate the passengers.
A high percentage of fire warnings are subsequently proven to be false. In the described circumstances and at a good airport with reliable fire services available, if there were no evidence of fire (hot floors, smoke visible, etc) I would be tempted to ask for the fire services to thermally image the holds.
[Note: they must not open the holds with pax on board]
If they determined no heat source I would then choose to either proceed to gate or vacate the runway and disembark the passengers by steps to avoid the inevitable injuries that would be sustained in an evacuation.
If they determined a heat source or one subsequently became apparent, I would evacuate the aircraft by slides.