The Twitter blog has revealed that it's finally going to be possible to have group chats with various people on the service. This is a feature that's going to be rolled out over the next few days/weeks so look out for it. Basically it's like Direct Messaging only you can choose up to 20 people to share the message with, and they can then communicate back and forth with each other, even if they're not all following each other.
So it's rather different to tweeting publicly to a group of people, which would be really helpful, but it's a step in the right direction. Twitter clearly wants people to stay on the site for a longer period of time, and this will certainly help in that - they're under pressure from various other tools out there such as the Facebook owned WhatsApp. It's certainly going to be helpful, and it does allow for time delayed discussions but we'll have to wait and see if it has the desired effect.
Twitter has also launched a video option for Android and iOS users. You can create clips of up to 30 seconds each and can also pull video out of your camera roll as well apparently. This is in many ways a far more interesting development, because you can really become a citizen journalist. People are used to taking photographs and sharing them, but this does move the concept to a higher level.