Pokemon GO

Version 0.19.1 is hot off the press with build date April 20. To put things in perspective, 0.13.5 was built on March 28th. That's a major version increment every 3.8 days. Let's have a look at the major changes visible in apk strings:

-New fast moves. All but one of them (Steel Wing) are entirely new moves, unseen in even the charge move pool. Niantic continues to add depth/complexity to the battling.

-New Move Strings
V0233_MOVE_MUD_SLAP_FAST
V0234_MOVE_ZEN_HEADBUTT_FAST
V0235_MOVE_CONFUSION_FAST
V0236_MOVE_POISON_STING_FAST
V0237_MOVE_BUBBLE_FAST
V0238_MOVE_FEINT_ATTACK_FAST
V0239_MOVE_STEEL_WING_FAST
V0240_MOVE_FIRE_FANG_FAST
V0241_MOVE_ROCK_SMASH_FAST

-Individual Pokemon now have the attributes: get_BattlesAttacked & get_BattlesDefended. Nothing made visible in game yet. This may relate to the Pokemon natures still seen only in the code and not in game, Stoic, Guardian, Protector etc.

-There's also a new Quickstart option in the settings menu. Looks like Niantic doesn't want the same questions from Australian testers asking what to do with gyms and Pokestops. There's now a quick tutorial slideshow in the settings.

-Addition of a battery saver service in the settings menu. Holding the phone upside-down will turn off the game render engine and turn the screen black.

-New popup warning you that when you deploy a Pokemon, you won't be able to access it again until it is knocked off. Code remains for "recalling" a pokemon but is not enabled.

-Some Pokemon have had their hit boxes re-sized for landing Pokeballs on them.

-Levels now require approximately 30% more XP.

-There's a lot of string changes to battles and probably invisible server side variables as well. Having spent a little time playing the game, battling seems to have been the main focus of the recent updates:

-There is now a button on screen (bottom right) to tap and quickly sub in a different member of your 6 attacking Pokemon. Think fast or take damage.

-Battles are much, much "tighter." Move animations don't lag behind the damage being done. Everything feels a lot less beta. Battling is fantastic and getting better.

-Health bars now float and follow the defender as they jump/move.

-The red targets on your character that flag incoming damage now "fade away" as you dodge out of them.

-UI Tidying: Energy bar being blue instead of pink. The flee button being larger and the countdown battle timer also being larger and moved to the left of screen.

Answering some questions and other bits not relating to the update:
Some old Pokemon players ask about the "best active Pokemon" to bring with them on their journey. There are no "active" 6 Pokemon. You have all your Pokemon at all times. The only Pokemon you can't interact with are the ones already deployed at gyms. When you attack an enemy gym, you do have to select which combination of 6 you would like to attack it with, but you are free to select any 6 you like from all your Pokemon.

In 500 Pokestop visits, I've looted a grand total of 5 revives in the beta. Letting Pokemon feint should be avoided at all costs right now. With the new hot-swap mechanic, this is possible, if you're fast.
Pokemon have to be at full health to be deployed. They do not have to be at full health to attack or be released.
You get xp credit and affect gym prestige even if your team loses, providing you defeated at least 1 Pokemon.

These last two points give rise to an interesting moral dilemma for beta trainers. Once you've fleshed out your Pokedex (100+ hours), there will be a lot of catching and releasing of weaker Pokemon. You can choose to catch and release on sight. Or, if you're a questionable trainer, it is currently entirely possible to line up 6 weak Pokemon you don't want and send them off against an enemy gym. The 6 of them should defeat at least one enemy Pokemon, weakening the enemy gym by at least 250 25 prestige and netting some XP. You can then release the feinted weaklings' shattered bodies and not consume your revives or potions. It's pretty dark. An interesting moral choice, but we'll see if it makes it through beta.

There is no player to player interaction implemented anywhere, be it chat, battling or trading. There is code referring to trading. But nothing has been implemented.
The beta is a 56MB download and unpacks to take up circa 200MB (including cache).
Edit Prestige seems to have changed. It now appears that 25 prestige is deducted for defeating each enemy Pokemon. A bonus 250 is deducted for clearing the entire team deployed. But even this doesn't fit 100%. Stand by.
Reminder: This is a beta, changing rapidly.