Using my USPtinyISP, I burned the LUFA CDC bootloader to my 32u4. Then I bootloaded Dean’s LUFA-based AVRISP mkII- compatible ISP firmware onto it. Finally, I used the 32u4 masquerading as a mkII to read and set fuses on an ATtiny13a.
What does this mean? It means that when the AVR programmer boards arrive from Laen, I ought to be able to quickly build basic firmware for them. Exciting!