I think 2,000 was a record club crowd for them. If they are aiming for Super League in 2009 then you'd hope number increase, and the Cardiff Super League weekend (Millennium Magic) will be designed to further promote league interest in South Wales.
The key for Crusaders is to get promoted up from the NL2 competition, where crowds of less than this are common for a lot of clubs, and start to play with some of the full time pro teams (Castleford, Widnes) in NL1 where crowds of 7,000 can occur. They missed out at the last hurdle last year, even though the RFL changed the promotion rules at the start of the season and essentially gave an extra opportunity for them to get a leg up.
I'd say if Crusaders can't be one of two teams to go up at the end of this season, they're no chance of having the momentum to be viable in SL from 2009. They have to go up to NL1, and then have a cracking start (promotions, coverage, crowds, sponsorship, finances etc) to the first half of 2008 to be ready, otherwise they are better served waiting a year or two? I'm all for it eventually, but sustainable expansion is the key, not rushing situations into potential failure.