I suggest that whatever effects may be observed on a given aircraft model will be characteristic to that aircraft and very dependent on just when the actions occur during the touchdown sequence.
If spoilers are deployed with a reasonable body angle (ie before the nosewheel is on the ground) then, with the usual (effectively) fullspan spoilers operating (by disturbing airflow on the aft portion of the chord), one would expect that the wing lift distribution would be skewed significantly forward which would account for a reduction in the nosedown pitching moment associated with the landing. The pilot would interpret this as a noseup pitching moment.
The magnitude of the pitching moment contribution associated with reverse will depend on the aircraft configuration (ie whether the thrust line is high, mid, or low geometry - height above the ground) and thrust levels achieved with reverse. The effect will be, however, a noseup moment contribution as reverse is a rearwards acceleration the line of which is located above the mainwheels
[ 16 October 2001: Message edited by: john_tullamarine ]