yes yes, you can go all J-TAG and replace the firmware with ease (well... if you arent an idiot) but instead of "uncapping" the connection, it's far smarter to just set the cap at a higher bandwidth. i personally can get speeds higher than the 5Mb limit from some sites (kernel.org) without any funny business, so i know there isnt an instant flag that is raised. so if you extend the cap to say... 7Mb, you may get away with it. oh... and updated versions of docsis work on newer surfboard modems. mine is compatible but i rather just wait and get fios.
"the wisdom of the wise will perish, the intelligence of the intelligent will vanish."