What's the 'arm in that?
ARMv6 processors aren't just limited to older Android devices, they are almost universally used in low to middle range phones as well. The popular Orange San Francisco (ZTE Blade) has a v6 processor, and that has an 800x480 screen, which is quite suitable for mobile browsing.
The problem for the average punter is that it isn't obvious which phone has which processor. The San Francisco has a Qualcomm MSM7227 processor. It *is* an ARMv6 based device, but you have to dig a bit to discover that. Try wandering into a local mobile phone emporium, picking an Android phone and asking the sales person if it has an ARMv7 processor because you want to run Firefox (and Flash, BBC iPlayer, etc).