Really like what Thomas has done - In my humble opinion I would use one of his concepts but would keep the original "retro" style rocket inside the little square icon.
I reckon the retro rocket is timeless and is a strong and recognisable brand inside the Joomla community. You can always modify or update the box it is housed in to suit current design trends etc...
Also Andy I do like the improved marketing slogan - "taking design to new heights"
Being a marketing and branding professional, I believe that the current logo has a brand history. Among those that would use RT templates, the current logo is well known and easily identifiable.
A question that you might ask yourselves is, "Can my logo be easily transferred to one color line art - letterhead, envelopes, etc.?" I believe that the current logo can.
I love the burst of excellent creativty, but I would hesitate changing the logo and the color scheme. It has added value to it already. Maybe a new site design using the same logo and color scheme. To me the site still has a year of usefullness left.