[eluser]Crimp[/eluser]
I am not sure the removal of Plugins in favor of Helpers is very helpful. Here's how I use the two:
1. Plugins
Examples of Plugins I often use are DOMPdf and HTMLPurifier. I place the nested project folder in the system-level Plugins and, that's right, plug a massive project into CI to extend it with a functionality akin to that offered by core CI classes.
2. Helpers
I use helpers just like CI intended. Typically just a few functions in a single file. Typically used for custom formatting in and across views. A recent example would be a forum_helper with time returned in plain language and search words highlighted, both helpful formatting functions repeated in views.
Now, these are two entirely different things in my mind. Even if a call to htmlpurify() may be construed as a one-trick pony, and thus no more or less than a helper, it comes with enough amazing and speedy baggage to make that pony employee of the month at the Pony Express.
Remember, also, that Plugins like HTMLPurifier even have their own internal cache (optional, ok, but a def. pluss). While it does not really matter what we call things and where we place them, as long as we can make them work, there is a logic and usefulness to working with meaningful structures - exemplified by familiar things like MVC.
Plugins made some sense. Now that sense is lost in the increased clutter of Helpers.
I am not offering my 2 cents for their return here. But I feel that the differences are worth thinking about.