Servers are getting cheaper. You get dedicated HW with 50GB traffic for about 45EUR/month, you only have to live with practically no support.
Even cheaper for start is a virtual server for 10EUR (1GB disk space, 15GB traffic), no dedicated HW, but you can install any software you want, like tomcat to use java servlets and have some freedom in configuring linux.
Now these offers (www.server4free.de
, all in german language) are possibly not usable if you want to make money with your server, as you would then need better support, backup service and uptime guarantee.
But to test a game server in the real world and find out customer acceptance it could be a nice low-cost solution. If it works you can always move your SW to another location.
I wouldn't wait for Sun offering any sponsoring. They would only support >98% finished SW and only very few of it, possibly you would have to sign too more papers than any time before and after a few weeks your SW would be shut down again.