Using Kaspersky Internet Security as a stop gap until Outpost is compatible with Vista. Although the firewall is not up to Agnitum's finest, it's doing a reasonable job - really miss decent logging though.
The rest of the suite seems okay, the Anti spam seems pretty effective and is at least detecting image spam better than Thunderbird did. Combined with Windows Mail's anti spam not a lot is getting through.
The anti virus seems very impressive as it picked up a lot of suspicious files that Bitdefender, CA-Anti Virus and Avast missed. Took a while to scan, but boy was it thorough.
I've tried most of the intergrated suites out there and I can honestly say this is one of the best. Personally, I really hate Zone Alarms interface (designed for the under 8's perhaps?) and Bitdefender was all red and lacked any real substance (I like lots of configurable settings and as much info on what the software is doing as possible)
Picked it up off ebay (1 year licence - from genuine Kaspersky reseller) for next to nothing which makes having to wait for Outpost a lot easier to bare.
Give it a try. I don't think you'll be disappointed.