I think if a city of the same size in England had a RL club who wanted to join SL and also had a long tradition of the sport being played there then nobody on here would question it. Let 'em in!
As for the ground - I think it's important that they do develop their current one rather than share with the RU lot. I think I'm right in saying that the Dragons had a less than pleasant time of it sharing with the local Vichyballers. I doubt very much Toulouse RU will be overly enthusiastic about a new show in town, best to have your own base than have an unhappy groundshare
May I say that I am delighted that RBS has used the term Vichyballers.
Toulouse could be huge - they have a treiziste tradition, they are in a fashionable, large wealthy city, they have shown in other fields that a lot of them will turn up to watch top class sport, Les Catalans have already shown that a French SL club can quickly overtake a number of the incumbents, we may get extra TV money.
Toulouse could fail - the player base may be too thin, people may not turn up to watch a team that loses every week, esp given the competing attractions, there may be no extra TV money, the Vichyballers may go out of their way to deny them sponsorship, access to facilities etc.
Given the size of the upside and that most of the risks can be assessed, and you would hope mitigated in advance, then they seem to have a compelling case.
I look forward to watching Nottingham take on Barcelona in 2015!
One final point, and like SOL I search the forum for any scraps of "evidence" that will confirm my entrenched position, I think this reinforces my view of the way forward for London as a host city for RL events. People will turn up if the quality is high enough and it is sold well enough. You don't necessarily need a franchise in a place to spread the word.