The Cleric is probably the most powerful core class (perhaps matched or slightly surpassed by the Druid), but it suffers a great deal for being seen as a distinctly support class, and a rather boring role. I really hate the notion that every group has to have a Cleric.
What I would do:
1) Increase skill points per level, and make more of the Cleric's spells and class features a bit more dependent on skills. The adjustments to Find Traps and similar spells are a step in the right direction; let's see more of that.
2) Reduce the hit dice to d6 (maybe) and armour proficiency to Medium (but don't assign Spell Failure).
3) Change healing. Preferably, adopt the Reserve Points option from Unearthed Arcana or just refresh the pool after each encounter, and either drop Spontaneous Healing... or just remove the spells entirely.
4) Make more of the Cleric's buff spells Personal. This makes the Cleric less of a support character, and more of a power in his own right.
Those are the mechanical things. However, I would also change the emphasis in the flavour text of the class. Remove mentions of the character healing and buffing other characters, remove talk of them as a support character, and instead play up their role as representatives of their divine powers, and try to make them a much more proactive class.
Also, you know those "Core Beliefs" articles in Dragon? The next "Deities & Demigods" should definately be of that mould, and much less concerned with giving us divine stats that will mostly never be used... and which are incompatible with the stats of any character who might challenge beings of that level anyway.
Alternately, drop the class entirely*. If it's such a chore to "play the Cleric", then it shouldn't really be part of a fun game. But, as long as that class exists, I suspect the mentality that you need a Cleric will always remain.
* In this case, I would recommend replacing it with three or four other classes, each of which fill one aspect of the Cleric's niche, but none of which is a direct Cleric replacement.