One objective for the partnership is to make all web content easily accessible on a mobile device, something that can often be hard to achieve. Speed and memory constrains are the biggest issue, so heaps of optimization would be in order. That is on their agenda, looking to provide hardware-accelerated browsing and video playback directly from web pages.
It isn't mentioned if Opera is actually selectively producing a version of their browser for mobile devices powered by Tegra. You can read more here.