Current status of concurrency: rails2.3/ruby1.9/thin

hi all,

i just got back from railsconf and forgot to ask a question. what is
the current status of handling concurrent requests? i am migrating to
rails2.3/ruby1.9 on thin and am confused about how many thins i need
and whether i can serve up multiple concurrent requests to them. in
front i use nginx for static files and ssl, pass the script requests
back to haproxy for load balancing across three webservers. in haproxy
i have set the usual mongrel/ruby1.8-safe maxconn=1 for each
instance.

in ruby1.9/rails2.3/thin i notice that thin seems to indicate that it
can handle 1024 request connections. does that mean that i can turn
off maxconn in haproxy?

in my reading of this group and other sites, i have read that ruby1.9
uses native threads and rails2.3 is supposed to be thread safe. does
that mean we are now ready to handle multiple concurrent requests
within a single app instance?

also, do i need to use neverblock or some other specialized db driver
to make concurrent requests happen?

lastly, i get the sense that all of this is just around the corner,
but not quite ready for primetime. is that an accureate assessment? if
so, what are the things that are lacking at this point?

thanks…gg