Skalds are not that good at PvE. They are very useful in RvR though for mid groups.
Shamans themselves are not excellent PvE toons, although they are very desirable and easy to get groups with in both PvP and PvE because of their buffs and endo.
As far as damage goes, skalds do more damage, but neither toon is going to get a lot of deathblows. Outside of healers, those two toons are two of the easier classes to get groups with in PvP. Shamans will definitely be easier to find groups with in PvE, as skalds offer very little now to a PvE group. Neither will be particularly easy to level up with solo.