There are a couple of things you can do to solve that problem very fast (workaround)
a) keep your site warm. I use www.host-tracker.com
to monitor my sites which as a side effekt seems to keep my sites warm.
b) you might want to have a look at this. http://www.iis.net/download/ApplicationInitialization
c) as usuall make sure your site is optimized. combine scripts, css wher possible. minimize css, use sprites for images (reduce host request), resize images in PS instead of SF.
d) wait for 5.1 which should bring what you are requesting in August. http://www.sitefinity.com/web-content-management/roadmap.aspx
Hope this helps for quick workaround, starters.