And...
raggi@mbk: ~/dev/ext/rack % g grep autoload
bin/rackup:autoload :Rack, 'rack'
lib/rack.rb:# All modules meant for use in your application are <tt>autoload</tt>ed here,
lib/rack.rb: autoload :Builder, "rack/builder"
lib/rack.rb: autoload :Cascade, "rack/cascade"
lib/rack.rb: autoload :Chunked, "rack/chunked"
lib/rack.rb: autoload :CommonLogger, "rack/commonlogger"
lib/rack.rb: autoload :ConditionalGet, "rack/conditionalget"
lib/rack.rb: autoload :Const, "rack/constants"
lib/rack.rb: autoload :ContentLength, "rack/content_length"
lib/rack.rb: autoload :ContentType, "rack/content_type"
lib/rack.rb: autoload :File, "rack/file"
lib/rack.rb: autoload :Deflater, "rack/deflater"
lib/rack.rb: autoload :Directory, "rack/directory"
lib/rack.rb: autoload :ForwardRequest, "rack/recursive"
lib/rack.rb: autoload :Handler, "rack/handler"
lib/rack.rb: autoload :Head, "rack/head"
lib/rack.rb: autoload :Lint, "rack/lint"
lib/rack.rb: autoload :Lock, "rack/lock"
lib/rack.rb: autoload :MethodOverride, "rack/methodoverride"
lib/rack.rb: autoload :Mime, "rack/mime"
lib/rack.rb: autoload :Recursive, "rack/recursive"
lib/rack.rb: autoload :Reloader, "rack/reloader"
lib/rack.rb: autoload :ShowExceptions, "rack/showexceptions"
lib/rack.rb: autoload :ShowStatus, "rack/showstatus"
lib/rack.rb: autoload :Static, "rack/static"
lib/rack.rb: autoload :URLMap, "rack/urlmap"
lib/rack.rb: autoload :Utils, "rack/utils"
lib/rack.rb: autoload :MockRequest, "rack/mock"
lib/rack.rb: autoload :MockResponse, "rack/mock"
lib/rack.rb: autoload :Request, "rack/request"
lib/rack.rb: autoload :Response, "rack/response"
lib/rack.rb: autoload :Basic, "rack/auth/basic"
lib/rack.rb: autoload :AbstractRequest, "rack/auth/abstract/request"
lib/rack.rb: autoload :AbstractHandler, "rack/auth/abstract/handler"
lib/rack.rb: autoload :OpenID, "rack/auth/openid"
lib/rack.rb: autoload :MD5, "rack/auth/digest/md5"
lib/rack.rb: autoload :Nonce, "rack/auth/digest/nonce"
lib/rack.rb: autoload :Params, "rack/auth/digest/params"
lib/rack.rb: autoload :Request, "rack/auth/digest/request"
lib/rack.rb: autoload :Cookie, "rack/session/cookie"
lib/rack.rb: autoload :Pool, "rack/session/pool"
lib/rack.rb: autoload :Memcache, "rack/session/memcache"
lib/rack.rb: autoload :Camping, "rack/adapter/camping"
lib/rack/handler.rb: autoload :CGI, "rack/handler/cgi"
lib/rack/handler.rb: autoload :FastCGI, "rack/handler/fastcgi"
lib/rack/handler.rb: autoload :Mongrel, "rack/handler/mongrel"
lib/rack/handler.rb: autoload :EventedMongrel, "rack/handler/evented_mongrel"
lib/rack/handler.rb: autoload :SwiftipliedMongrel, "rack/handler/swiftiplied_mongrel"
lib/rack/handler.rb: autoload :WEBrick, "rack/handler/webrick"
lib/rack/handler.rb: autoload :LSWS, "rack/handler/lsws"
lib/rack/handler.rb: autoload :SCGI, "rack/handler/scgi"
lib/rack/handler.rb: autoload :Thin, "rack/handler/thin"
I don't think we have a bloat problem. I think you're judging bloat the wrong way.