Anyone watch the WTA tour? They actually allow coaching during most of their tournaments.
Effective? Are these girls getting that little bit of information that will make the difference between winning and losing?
Doesn't look to be the case to me.
I refuse to admit that I watch WTA matches. 
As you stated earlier, your position is that coaching enhances the game.
That doesn't seem to be the case in this post.
Which way is it Babs???

To me, it doesn't look that constructive at times. But from watching that video I linked, I can see that it may be. If the guy says it does affect the WTA matches, in a way that improves the quality of the match, that cannot be a bad thing.
I guess there we (collectively) are of two minds:
1. Most people don't want coaching because they believe that in
this individual sport, the player should be an island and problem solve. Can't think of another individual sport that doesn't have in-match/in-play coaching.
2. Then there are those like me, who would rather see a match of higher quality. If that can be done via coaching, then I would be OK with a rule change allowing for in-match coaching.
Ultimately, the player still has to do the problem solving regardless of how much he was coached before the match or during. Both players will be making adjustments to what the other is doing. For instance, in the case of Petrova and Henin, Petrova will have to problem solve now that Henin has taken the serve out wide away, and so on...