In practice, I've found the Shaman list to be pretty effective as it is. Some of the spells were changed in the 3.5 update, and it actually did more to help the shaman than to hurt it. It has very few poor spell choices and a number of really good ones without having too many that are truly game breaking.

Summon Nature's Ally and Spirit Ally are both good spell lines, the second being unique to shaman. The Possess line can also be an instant win but is a bit trickier to use.


1
On another note, Shaman had a decent update to 3.5 in Dragon Magazine #318, p 34.
Explicit updates:
  1. Unarmed strike was updated to the monk's entry but had it's own progression (1st-5th: 1d6, 6-11: 1d8, 12-17: 1d10, 18-20: 2d6).
  2. Bonus Feat list was updated.

Due to other changes in 3.5, the animal companion feature is generally assumed to updated to that of the 3.5 druid as well. Deleted spells are removed from the list, and updated spells are updated as normal.

1On another note, I've recently been working on my own take on Shaman. It veers away from the traditional spellcaster route, but I think it work pretty well.