Exchange both clash of wills for dissolve, and caves of koilos for languish.  Wil probably need to remove ugin at this mana point.

Mainboard Changes:
- Dragonlord Silumgar
+ Silumgar, the Drifting Death
- Foul-Tongue Invocation
+ Temple of Silence

Sideboard Changes:
- Virulent Plague
- Dragonlord's Prerogative
+ Foul-tongue Invocation
+ Ugin, the Spirit Dragon

Updating for Origins a bit...

Mainboard Changes:
- Crux of Fate
+ Languish
-2 Dissolve
+2 Clash of Wills

Sideboard Changes:
- Drown in Sorrow
+ Crux of Fate

I still haven't modified this decklist.  I went 4-0 at the turnament last monday, and 3-0-1 at the prior tournament (the draw was intentional, and when we played it out, I won anyway).  I think I am in the zone with this deck now.  I'm not sure if it is that the decklist is positioned really well against the shop I play at or if my comfortability playing with the same deck gives me an advantage.

Since the last changes, this deck has been performing very well.  I pretty much haven't lost any matches against friends in about 2 weeks.  It also played well at last monday's trounament (4-1-0).  In the match I lost.  I won game 1, lost game 2 and 3.  On game three I kept a 4 land hand with no black sources.  Had I mulliganned, its possible I could have taken that game as well.

Mainboard Changes:

- Dissolve

+ Thoughtseize

I think this is a good choice.  I usually like having counter's to help me protect Ojutai on an attack.  Thoughtseize can do something very similar, a bit easier, and with less mana issues.  It also has the benefit of being useful turn 1 or many other turns.

Mainboard Changes:
-2 Anticipate

+1 Dissolve

+1 Foul-Tongue Invocation

Anticipates have just felt too slow in a lot of cases, and I am usually looking for a counter or removal, so I just went directly there.  I'll try it out for a bit and see how it works.

Mainboard Changes:
+ Ashiok, Nightmare Weaver

- Flooded Strand

Sideboard Changes

- Ashiok, Nightmare Weaver

+ Perilous Vault

Mainboard Changes
+ Haven of the Spirit Dragon
+ Dragonlord's Prerogative

- Utter End

- Disdainful Stroke

- Plains

Sideboard Changes

- Utter End

As great as utter end is and as useful as I found it at times, I just don't think its worth the added complexity in the manabase.  Removing it makes ojutai the only splash, which makes haven's viable.  Haven's then enable recycling from graveyard.

Mainboard Changes:
+ Haven of the Spirit Dragon

This puts the deck at 61, this will increase my likelihood to draw a land, but not as much as if I dropped another card out.  It also decreases my likelihood to draw everythign else.  I probably need to remove another land, or card.  Probably ultimate price, but I'm not sure.