Going out of beta we had to decide on something which was really carrying what the app is, we loved Vector but it has always been a code-name and a nice pun on Matrix :)
Riot is more representative of what the app can do and its ambitions! Break the barriers between apps, give the control back to the user to choose their client, if they want to encrypt, host themselves, tune the notifs, the fact it's open, built on the open ecosystem of Matrix and thus benefiting of all the integrations and bridges built for Matrix.... Sounds pretty revolutionary to me ;)
Worth noting that only the name changed: the app and the team and the openness are still the same (modulo new features)!
I don't get why you would rename Vector, feels like everyone recommending 'Vector' to friends and family has wasted their time.
But at the end of the day, it's just a name, so I'm not too upset about it.
it doesn't feel to me as a stronger brand later (both are fairly random words for many people if you don't look at an explanation)
violent connotation (CNN headline: "protesters organised using the encrypted Riot app").
potential confusion in tech-y circles with Riot the gaming company (which could totally be in the market to offer a messenger, given that they run one of the biggest online games), for Vector I didn't have any other project in mind.
In the end it's just a name and it won't make or break the app for me, but I personally don't see the benefit of the new one.
including http://riot.com/ - http://riot.io/ - http://riot.org/