Yeah, placeholders, but it means that things you fight don't stand around like derps while you kick the crap out of them.
Battles no longer crash the client.
There's a little splash graphic midscreen when you start a battle.
Pet battle stuff is listed in the chat box in a much more readable manner
Trap lights up more noticeably when you can capture something.
If you fail a trap, the enemy pet will keep attacking your pet, so make sure your pet is at good health!
Shy Bandicoons in Valley of the Four Winds are indeed capturable.
When you capture something, you get a splash mid-screen like when you gain a level.
Lots of critters added to the pet journal (ones that had previously been in game but not capturable):
-Adder (Various places)
-Alpine Chipmunk (various places)
-Alpine Hare (Dun Morogh/Winterspring)
-Arctic Hare (Borean/Dragonblight/Zuldrak)
-Ash Lizard (Hyjal/Ungoro)
-Ash Spiderling (Searing Gorge)
-Ash Viper (Burning Steppes, SMV)
-Bat (EPL/Tirisfal)
-Beetle (Various)
-Biletoad (Sholozar)
-Borean Marmot (Tundra)
-Brown Marmot (Hinterlands)
-Carrion Rat (Hyjal)
-Cat (Elwynn/Eversong/Netherstorm)
-Chicken (Elwynn/Fjord)
-Cockroch (DIFFERENT from the vendor one - various places)
-Coral Snake (Stonetalon)
-Crimson Moth (North/Cape STV)
-Crimson Shale Hatchling (Deepholm)
-Crystal Beetle (Deepholm)
-Deepholm Cockroach (Deepholm)
-Deer (various)
-Desert Spider (kalimdor deserts)
-Dung beetle (Durotar/Uldum)
-Dusk Spiderling (Duskwood)
-Elfin Rabbit (Darn/Teldrassil/Hyjal)
-Emerald Boa (Uldum/Ungoro/NBarrens)
-Fawn (Elwynn/Teldrassil)
-Fire Beetle (various)
-Fireproof Roach (Hyjal)
-Fjord Rat (Fjord)
-Forest Moth (Ashenvale/Darn/Desolace/Hyjal)
-Forest Spiderling (North/Cape STV)
-Frog (Ashenvale)
-Garden Frog (Jade Forest)
-Gazelle (NOT the Fawn - Desolace/Mulgore)
-Gold beetle (Badlands/Tanaris)
-Grasslands Cottontail (Arathi)
-Grizzly Squirrel (Grizzly Hills/TwiHighlands)
-Grotto Vole (Hyjal)
-Grove Viper (Jade FOrest)
-Hare (Durotar/Hinterlands)
-Highlands Mouse (TwiHigh)
-Highlands Turkey (TwiHigh)
-Horny Toad (Desolace)
-Huge Toad (various)
-Infected Deer (Bloodmyst/Silverpine/EPL)
-Infected Squirrel (Bloodmyst/Silverpine/EPL)
-Irradiated Roach (Dun Morogh)
-Jungle Darter (Jade Forest)
-Jungle Grub (Krasarang Wilds)
-Kuitan Mongoose (Townlong Steppes)
-Larva (Ghostlands)
-Lava Crab (Burning Steppes/ Searing Gorge)
-Leopard Scorpion (Uldum)
-Lizard Hatchling (North/Cape STV)
-Locust (Uldum)
-Long Tailed Mole (STV/Dun Morogh/Uldum)
-Mac Frog (Uldum)
-Maggot (Various)
-Masked Tanuki (Jade Forest)
-Mirror Strider (Jade Forest)
-Parrot (Various)
-Prairie Dog (not the vendor one - various)
-Rabbit (Various)
-Rabbot (Winterspring)
-Rabid Nut Varmint 5000 (Azshara, Stonetalon, Winterspring
-Ram (not little blac - Hillsbrad/Loch Modan)
-Rat (Various)
-Rat snake (duskwood)
-Rattlesnake (Badlands/TwiHigh/Tanaris)
-Red Tailed Chipmunk (Various)
-Redridge Rat (Redridge)
-Roach (Various)
-Robochick (Azshara/Winterspring)
-Rock Viper (Various)
-Sandy Petrel (Jade Forest)
-Scarab Hatchling (Silithus)
-Scorpion (Various)
-Sea Gull (not the TB one - Elwynn)
-Sheep (Various)
-Shimmershell Snail (Darkshore)
-3 different versions of Shore Crab found in different places
-Sidewinder (Silithus/Uldum)
-Silkbead Snail (Jade Forest)
-Silky Moth (Hyjal/Ungoro)
-Skittering Cavern Crawler (BEM)
-Skunk (Various)
-Small Frog (Various)
-Snake (Various)
-Snowshoe Hare (NOT the same as Snowshoe Rabbit - Hillsbrad)
-Snowy Owl (Winterspring)
-Spider (Various)
-Spiky Lizard (Badlands/Silithus)
-Spiny Lizard (Durotar)
-Spirebound Crab (Jade Forest)
-Spotted Bell Frog (Ungoro)
-Squirrel (Various)
-Stinkbug (Tanaris)
-Stormwind Rat (Various)
-Stowaway rat (Deepholm)
-Stripe Tailed Scorpion (Various)
-Summit Kid (Kun Lai Summit)
-Swamp Moth (Swamp of Sorrows)
-Tainted Cockroach (Felwood/SMV)
-Tainted Moth (Felwood)
-Tainted Rat (Felwood)
-Temple Snake (Jade Forest)
-Toad (Various)
-Topaz Shale Hatchlnig (Deepholm/Desolace)
-Tree Python (STV/UNgoro)
-Tundra Penguin (Dragonblight)
-Turkey (Fjord)
-Twilight Beetle (Various)
-Twilight Spider (Various)
-Undercity Rat (Tirisfal)
-Water Snake (Various)
-Wharf Rat (Cape of STV)
-Wildhammer Gryphon Hatchling (TwiHigh)
-Yellow Bellied Marmot (TwiHigh)
Apologies if I missed any; it's late.