If you set the homepage to blank (menu (when you're in the browser). Settings. Set Homepage.
Set the homepage to
about:blank
Click OK and in Jellybean (and maybe earlier browsers), don't forget to click Done (upper-right corner).
The browser will go to a blank page when you press "homepage", but I haven't found a way to clear out the bloat (and that's what it is - the carrier wanting you to go to THEIR homepage) on first opening the browser.