We've seen a few minor outages for Siri since its debut, but those were minor blips compared to what appears to have been a more widespread, longer lasting outage that took place earlier today in the US, Europe and South Korea (according to Electric Pig -- we can attest to seeing an error message with the service in the US, and BGR noted it as well). We asked our Twitter followers and some reported brief outages last night, but others said it's been unavailable for hours and is still down.
Of course, when Siri was announced, Apple noted it was "in beta" but I took this to mean (and Apple seemed to suggest) the "beta" meant they were adding more languages later (like Scottish?). Just like, for example, that "beta" at the top of the TUAW page, meaning "we'll keep adding features." The problem with a Siri outage, as opposed to an iCloud one, is that Siri is designed to be used at any time, hands-free, to perform multi-step tasks. When the service is offline, you can certainly do those tasks, but you can't do them by speaking into your iPhone. You're not going to see this illustrated in the Siri ads, that's for sure.
I don't intend to write up every Siri outage here on TUAW. Like MobileMe status posts (oh, did I mention iCloud IMAP also seems to be down as I write this? Apple still can't seem to grok simple email, but I digress), it will become a futile task as we chase down the percentages and Apple improves the service. Still, I think it is notable that when a competitor like BlackBerry suffers a global messaging failure (one of their "core strengths," remember?) we laugh, but when Siri goes missing we tend to shrug it off. Yes, the service is in beta, but here's hoping Apple can beef it up once more of us become addicted to telling our phones what to do with our minds.