I saw those one-IC solutions but I am hand-soldering (for now at least) so QFN packages are out. From Maxim, I saw the charger IC I mentioned above (MAX712/713) but at second look I'm not sure if it's realistic given it's voltage requirements.
As I mentioned above, the idea with this circuit is to power a typical Arduino that's using a 7805, which means that both the battery and wall wart have to be between 7.5 and, say, 12v. To me, that made the SEPIC topology attractive because the wall wart and the (fully charged) battery could be pretty much the same voltage. If I went with the MAX713, I'd need the wall wart to be significantly higher (it wants 1.9v * cell count + 1.5v minimum), which means I'm burning off a lot of waste in the Arduino's voltage regulator when it's operating on wall wart power (which will be 99% of the time).
I suppose I could put a voltage regulator on this circuit and feed the Arduino's 5v pin instead of it's Vin pin, but my particular Arduino has a pH amp circuit that needs a Vin > 5v so that solution is out.
Total current requirement is unknown but there's a lot on my 'duino clone (two 328p's, an MCP23008 for an LCD, an ENC28J60 Ethernet interface, the pH circuit mentioned above, etc.) so I'm guessing it's not going to be low.