Raspberry Pi interview: Eben Upton reveals all (Linux User)

Truetype rendering is CPU-intensive but not unmanageable. I remember using outline fonts on an Archimedes with 8MHz ARM processor. They were rendered into bitmaps (with sub-pixel anti-aliasing and hinting) as needed; it took a fraction of a second per glyph after which the bitmap was cached for future use.

You are right, though, that it is much more power-efficient to have a traditional CPU core do these things rather than force a big lump of GPU silicon to do tasks it's not well suited for. I was thinking only of making the cheapest hardware possible for something like the Raspberry Pi, which doesn't run from batteries.

(By HTML I meant rendering only, not Javascript execution; these days with reasonably quick Javascript engines even most web applications spend most of their time idling the CPU, waiting for the next keystroke.)