1st and most important is that I hope Brian and Roger make more music before they quit. I am indifferent as to whether they do together or seperately as far as the studio situation goes. Together with Paul is a bit more interesting, but 2 solo albums is twice as much as one group album, though the one album would contain the best part of what would divide into 2. As for Paul, I like him as a musician, but he does taint the purity of B and R's music, and yet he makes up for most of his influence by his superior vocal skills, and furthmore his style does blend uniquely well with Brian's style specifically.
What makes the difference most is the tour potential with Paul Rodgers. This alone answers any questions I have about him and makes his presence totally welcome to me.
As for another album, I would love to see their chemistry develop further after their first experience which worked out well, and a further tour tightening them up even further.
A 2nd album would be great, especially with considerations towards getting a 4th entity to help guide production, the person I have in mind would be a long overdue reunion with Roy Thomas Baker as Co-producer with Queen for the first time since Jazz was made 30 years ago. WIth that in mind, I would like to see a return to classic style with heavily produced Queen, lots of vocals, lots of guitar, etc...
The biggest thing missing from Cosmos Rocks is the ambition of Queen to set out to make a truly epic product. I felt like this one was done more as an experiment, keeping fun and a light amount of seriousness to the project.