Goober, Fang - don't worry...they're real, honest, all real!!!
In all seriousness though - who's to say that they're faking it? There are always rumours around the music business and Hollywood and how are you going to confirm what's true and what's not...
I personally haven't seen an article where they openly admit that the "lesbianism" is a scam but so what... Madonna pulled some crazy stunts for publicity and I think she did okay for herself. If Julia and Lena wanna pretend in order to make it big, by all means pretend away - just let me sit back and enjoy watching them grope each other.
Here's an article that alludes to the fact the "the group" is manufactured but says on one hand that the girls hide behind the language barrier to avoid answering difficult questions about their relationship but then goes on to quote Lena as saying that they are in a relationship and it's normal for a girl to love a girl...
http://www.alterheros.com/english/edito/index.cfm?recordID=10