The Secret of Dynamic Queue that Might Screw You
You'll still need to be of similar rank to your queue-buddies, and the system is designed so that groups will almost always play against similarly grouped opponents (so if you're in a premade five, there's a 95% chance you'll run into another premade five), but now you'll be able to compete the way you want to.
Anyone else have a huge problem with this comment? Yeah, 95% of the time a 5 man premade will go up against another 5 man premade. So what about the other 5% of the time? We all know how powerful communication is in league which means that in these 5% of games the premade will be highly, highly favored, especially since queuing with multiple people doesn't increase your MMR anymore.
In a system where most people hover around 50+/-5% win rate, this 5% becomes a HUGE factor. It can single handedly be the difference between you climbing in rank or falling, punishing people who don't have lots of friends that play league or who are of a much higher/lower ranking then their friends. Furthermore, the ability to queue with 2, 3 or even 4 of your friends means that poor players will be able to climb much higher than their actual skill level as long as they have a good group of friends to carry them.
TL;DR I truly fear that solo queuing will negatively impact your ranking in Season 6. Also, dynamic queue will make individual skill less important to climb in ranked because you can queue up in a premade to carry you.