Hi,
Thanks to Gavin Andresen for proof reading and suggesting clarifications. Thanks to Patrick Strateman for suggesting the hierarchical format and pointing out some flaws of browser user-agents to me.
The timeline is written in the past tense since BIPs are meant to be readable in the future for explaining why we took certain decisions with bitcoin. A nice cache for future historians when bitcoin is ubiquitous ;)
The next version 0.6 should be the protocol version which becomes peeled off from the current client. There are still some changes migrating into the protocol that need to be finished.