SPDY certificates and Wordpress multisite

[cachito]

Hello. I manage a small blog network (17) that has a lot of traffic (20MM
visits/month). I use Wordpress Multisite to manage it, each blog has its own
domain name, and all are served from the same WP install.

I'm thinking about implementing SPDY to speed up the sites, I know I need
SSL certificates for this to work.

1) Will I need a certificate for each website? Or just one certificate for
the main site to encrypt the connection and that's it?

2) I have a single server directive holding most of the configuration stuff
with 'default_server', and then some individual settings for each site,
mostly www-to-no-www redirects and legacy url rewrites. If I need a
certificate for each website, do I need to replicate all the wordpress
config for each domain, having a complete server directive with all WP + PHP
stuff in it for each domain? Does this impact nginx's performance in any
way?

This one's just lazy: is the RPM package hosted in the nginx repo (for yum
in Fedora/CentOS, etc) compiled with SPDY on or I'll need to compile my own
version?

Thanks in advance.

Cheers!

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,239609,239609#msg-239609