+1 for not forcing a standard on. (Talking from the perspective of organizing smaller events)
If we standardize on 'Hackathon', we'll have people coming in and asking us 'how to crack fb?'. If we call it 'Workshop', we'll have people coming in asking for certificates (or wondering how much to pay for it). DevCamp avoids these problems by being completely ambiguous :P
Every event needs associated messaging to reach the right audience and to set the right expectations. Workshops and hackathons are also fundamentally different events - Workshops are 1 to many knowledge transfer + hacking, while hackathons are much more distributed 'get stuff done' type things. Without proper messaging, people might come expecting the former, and be disappointed to get the latter (or vice versa). Forcing a convention would make the problem worse.
TL;DR: -1 to standardizing for names, let whoever is organizing it figure it out.