The reason that Keeper doesn't run Tog (Ze Germans experimented with it last year) is because Keeper doesn't play draw spells.
I absolutely agree to this. Keeper is one of my favourite decks, and has served me well often enough, up to a 6-1 finish in Dülmen. Still, it lacks a lot of things compared to Hulk and Slaver-builds: It does not have the punch that Mindslaver provides, and it does not have the card drawing of Hulk, which makes every game with Keeper a nerve-wrecking gamble. Yes, Keeper can win every game. But it needs extreme concentration on behalf of the player, a very good knowledge of what to tutor for in which situation, and also more luck than most other decks. (Granted, Keeper is built to optimize your luck, but still.)
Compared to other top decks in the format, Keeper is still the least redundant deck and about the most reactive thing you can play (as jp already pointed out, but this needs to be stressed). Keeper usually has no real game plan, unless you call "stay alive and drop a win condition" a game plan. What is it that the 4-color-control decks we are used to call "Keeper" really do? They rely strongly on their opening hand to stop an initial rush, and then hope (and try) to draw into either Will or a Decree/any win condition of choice, getting rid of any problem in between.
That is, btw, why Exalted Angels are good. They give you an alternative game plan: "Suicide Angel", translating into "drop an Angel in the first three turns and ride it home".
However, I think that 4c-Control-decks will always see play and will remain in the position to place high every time, but rarely win a tournament. I believe this has been said before: Over the course of a tournament, a properly metagamed Keeper will win most matches, but not all. To me, playing Keeper feels like having a 50% chance against any deck -- no specifically good match-ups, but no specifically bad match-ups either. The old Azhrei saying along the lines of "a Keeper is like a hot, high tempered woman: At times, she'll turn away from you, at other times she takes you on a hot cajoling ride" still is true, in my opinion.
So, to answer the initial question: Yes, Keeper is a wonderful deck. However, in terms of power, redundancy and consistency, it is being surpassed by a lot of decks. It is still a force that needs to be reckoned with, but it is actually second choice when it comes to tournament-winning decks (all other considerations excluded, like nostalgia, mental challenge, belief, and tradition).
Throwing a look into the future, I think that actual control decks, of which Keeper is a key represantative, will --for the next step of their development-- need to look into other areas of card drawing and are likely to re-evolve into aggro-control decks or at least incorporate some aggro-control elements.
Dozer