Google’s focus is on reducing latency between client machines and servers, and in particular, reducing the number of round trips (either client to server and back to client, or vice versa) required. When data is sent over a TCP connection, its receipt must be acknowledged by the receiving end. The sending end can only send a certain number of packets before it must wait for an acknowledgement. The time taken to receive an acknowledged is governed by the round-trip time (RTT). With high bandwidth, high latency connections, clients and servers can end up spending most of their time waiting for acknowledgements, rather than sending packets.
More far-reaching than these SSL tweaks is Google’s proposed alternative to the HTTP protocol that underpins the Web: SPDY.