I'm not saying they're exactly equivalent, but let me make the my reasoning more concrete so you see what I'm talking about.
With respect to a new OS release:
(a) When can people outside of the OS developer / OEMs and relevant carriers first use the new OS version?
Android: When the Nexus device launches
iOS: With the iOS public beta
(b) When do developers get the SDK for the new release?
Android: Shortly before or around the Nexus device release
iOS: With the iOS public beta
(c) When is the new OS release "done"?
Android: Some number of x.x.x releases after the initial Nexus launch (probably 4.0.3 for ICS). For example, at least one core Android developer said that they didn't get ICS working on anything with less than 1GB RAM (or a 720p screen is a logical inference given the possible devices) until 4.0.3 on the Nexus S! I don't know what to call Android 4.0, but I'm sure "done" doesn't fit.
With respect to a new OS release:
(a) When can people outside of the OS developer / OEMs and relevant carriers first use the new OS version?
Android: When the Nexus device launches
iOS: With the iOS public beta
(b) When do developers get the SDK for the new release?
Android: Shortly before or around the Nexus device release
iOS: With the iOS public beta
(c) When is the new OS release "done"?
Android: Some number of x.x.x releases after the initial Nexus launch (probably 4.0.3 for ICS). For example, at least one core Android developer said that they didn't get ICS working on anything with less than 1GB RAM (or a 720p screen is a logical inference given the possible devices) until 4.0.3 on the Nexus S! I don't know what to call Android 4.0, but I'm sure "done" doesn't fit.
iOS: When the OS is released