Does it still support the Streetpass-esque features of the DS release?
Not anymore as far as I can tell. You can connect with other people to trade Friend Cards but there doesn't seem to be a way to leave it running in mingle mode in the streetpass-like way the DS version allowed.
(Rest of this post has to do with differences regarding mingle mode and is a minor thing depending on how you look at it, but I'll be thorough for anyone interested.)
For anyone not familiar with this, PP (Pin Points) are the points used to level-up/evolve pins. There's also the thing with PP mixing but I won't go there. Mingle PP is a certain type of PP that you can only get by connecting with other players. This is the way it worked on the DS:
http://twewy.wikia.com/wiki/Mingle_Mode
http://twewy.wikia.com/wiki/PP#MPP
The other types are Battle PP, that you get from normal battles, and Shutdown PP. Shutdown PP is still present in this version. It's a kind of PP you get while you're not playing the game, and it goes for the pins on the deck you had equipped when you stopped. Thing is, the game only clocks your non-playing time if you go back to the main menu. I can't see any way in-game to "go back to title", so you have to kill the app on the multitask bar if you're done playing for a while and want to get SDPP. Anyway, both BPP and SDPP work the same on iOS.
Mingle PP was one of the criticisms some players had with the original game due to how annoying it was to obtain. I was testing mingle in this version and it seems to be even more impossible to get Mingle PP now. There doesn't seem to be any way to get "alien" connections (which were random bonuses and connections to any wireless device, not necessarily a DS) in order to acquire MPP like you could in the DS version, and the wireless modes where you trade Friend Cards and play Tin Pin Slammer with other people actually require you to be physically close to someone with an iPhone or iPad with a copy of the game and bluetooth turned on. This is not ideal because some pin evolutions are only attainable with Mingle PP (in this version too, as mentioned in the help section of the mingle menu).
What this all means is that this makes it virtually impossible for some people to go after all the 304 pins you can get. Assuming they didn't change the pin chart, these are the pins you can only get by using MPP (I pulled this list quickly so if anyone sees something wrong, tell me):
Pin 004 - Blizzard Cool
pin 015 - Beauty Launcher
Pin 019 - Sparkle Beam
Pin 041 - Meteor Hook
Pin 042 - Meteor Spike
Pin 051 - Rapier Glance
Pin 089 - Mikazuki
Pin 115 - Wassup Voltage
Pin 120 - Vacu Squeeze
Pin 123 - Gimme Dat Hippo
Pin 140 - Velocity Tackle
Pin 143 - Go 2 Heaven
Pin 153 - One Grain, Infinite Promise
Pin 161 - June Hearth, January Fan
So yeah, only 14 out of 304. Skills-wise some of them are unique and some have powers that are similar to other pins. There are more pins you can get by MPP evolution, but those can also be acquired by other means like drops, shops and normal evolutions. In the end this only affects completionists who want all pins but won't be able to find someone in real life with a copy of the game on iOS.
Ironically, this time it will be easier for me because I have a close friend who bought the game. I'm still disappointed in this implementation because there's no reason they couldn't make it possible to play Tin Pin matches online or find people online to trade Friends Cards with by using the GC friends list or something in that vein. Best case scenario they'll change how this works with an update and tweak it to work online, at least with the Tin Pin Slammer matches. Probably not happening.
tl;dr:
- Battle PP: play the game normally.
- Shutdown PP: requires you to go back to the main menu like in the DS version. With the DS you just had to turn off the game but on iOS terms this means you have to kill the app as there's no "quit game" option.
- Mingle PP: sucks even more now. You can only get it by knowing someone in real life who has the game on iOS.