Ideas/Discussion for a Role Based Queue System

I had the idea that a queue system that implemented some sort role sign up would be nice for games which you want to practice a certain champion. I also found a thread already talking about something similar here

The System Could:

• Allow players to label themselves as a certain role (Range AD, AP Caster, Support, Tank, Jungler, Other, etc.)

• Let players choose 4 more roles they want to be matched with (repeating roles accepted)

• Group players by their desired team

• Roles can be switched

What are your ideas about this? How do you think that this sort of system could work/be implemented?

EDIT BELOW:

First off, Yay for discussion. Secondly I'm seeing alot of comments about this system having increased queue times. So I think I should point out that this system should/would be separate and optional to the current queues. This still allows people to still do what they always do and queue first an setup the team comp in the champion select. What I think some people are saying is that because of the increased queue time that comes with this system no many people will use it.

So now I have more questions

How do you guys think this could work in a way so that queue times are not outrageous?

Also I understand that if a system like this was implemented it might be unpopular, but I don't think that's a bad thing. For instance, it seems like the 3v3 map Twisted Treeline is unpopular to the majority of this community, but I really like its inclusion. I feel that it enriches the games content and even though I don't play it often I am glad it is there.

P.S. Anyone know how to create better spacing between 'paragraphs', this looks like a wall of text and I don't wan the formatting to put people off from reading it.