Rails should be faster and leaner, Rails must have a central page on the rubyonrails.org website dedciated to deployement, scalability and maintenance of rails applications, Rails should have tools to benchmark code and see what sections of the application should be improved to reduce request processing.

I hate creating dozens of CRUDS for admin areas for some of applications. In many applications it can be done in the frontend, but there are situations when you just can't do that.

The public and plugin API should be defined and tested.

It would be great to have a copyleft Rails 3.0 book explaining the various concepts of the framework. Instead of waiting that the book is finished to start the translation work, it could be done in parallel by the community.

Sometimes I have forms with no obvious AR counter-part that I'd like to validate using AR's excellent validation module. It can be done but not without some hacking. It would be nice to be able to mix in validation support to any class.

overused of metaprogramming and overly clever code in general in Rails is annoying: it is very hard to read

Plugins are really no different than gems. Why have both systems?

ActionMailer is currently decoupled from ActionController, so changes that have been made to ActionController since the early days of Rails have to be hacked onto AM in inconsistent ways.

Let's abstract a common superclass or mixin and use it in both ActionController and ActionMailer. This will bring ActionMailer up to par with ActionController in the short term, and will help avoid feature drift in the future.

Currently, ActiveResource (ARes) is similar to ActiveRecord, but it doesn't have the same polish or ease of integration. For example, it is not possible to declare validations on an ActiveResource class or for ActiveResource objects to be part of an association.

Let's give ARes some love!

How mail is really different from say XMPP notifications? Or AMQP, for non-human? Rails needs a unified messaging interface like merb-messenger.

I want an easy way to achieve the sort of dynamic subdomains you see on blogspot and even basecamp. I know there are ways to do it via plugins and such, but I'd like it to be significantly easier than it is now.

Rails ActiveRecord make easy to work with a relational SQL based database but there's a few support for the non-relational ones, like a document-oriented database. In many cases the non-relationals databases are a better choice.

Nowadays, more and more people (like me) are using alternative testing solutions like BDD, or alternative Javascript/Ajax approaches like jQuery. Rails is bound to Test::Unit and Prototype right now, and this should be an open decission by the programmer, not by the framework itself... what do you think?

As part of the merge of Merb and Rails, it is very natural that parts will be ported also. It is very needed in some applications (including mine). Makes the app much more modular. I use now cells as a compromise (I use it for my widgets architecture), but it must be in rails core.

Like in DataMapper.

In cases where bulk update type operations and/or repetitive queries are required, allowing for SQL statements to be prepared and then have variables bound to them can improve performance significantly.

DataObjects provides a clean, ruby-like API into postgres, sqlite3 and mysql. Using it behind AR would greatly simplify the AR Adapter code.