I understand that's what Java does, but if I wanted to be writing Java code,
I would be. PHP != Java, and I think the language (and PEAR) is mature
enough for decisions to be made on this topic without concerning ourselves
too much with what the big kids are doing.
I think you're missing the point here. The overwhelming position for OOP languages (which PEAR is all OOP) has been humpBack. Moving from Java to Python to Ruby to PHP it would make sense that of 3/4 use humpBack that we stay consistent with the rest just so people don't have to retrain their CS thought processes ... it makes for a smoother transition for people moving from Java to PHP for instance (of which there are a lot - more with PHP5 I suspect).
The PEAR foundation classes use lowercase_and_underscore, and IMHO other
packages (whether they are popular or not) should have followed that example
wherever the CS guide was vague.
Well, we can't turn back time either. I don't think forcing foo_bar down everyone's throats is for the best. I think a more pliable approach of "keep it consistent in your package" is much better overall.
Also, despite packages being grandfathered in, you'd have HUGE API changes between Net_Curl and Net_Curl2 for instance. We're not talking about upgrading and fixing a few BC problems in your code, we're talking about changing ever single variable name you use. As it stands now I only have to change my require and, possibly, a few function/variable names/calls. If your proposal, as it stands, were to be adopted I'd be changing EVERY variable name in ALL of my code. That's just not practical.
--Joe