At the Analyst Day event, Google revealed what we can expect from a new version of Gmail that will launch soon:

• prefetching messages. When you load a page that contains a list of messages, Gmail will fetch them in advance so that when you need them, they'll be available instantly. Google said that Gmail will have a completely new JavaScript architecture that will bring a much better performance.
• a new contact manager that will be shared with other Google apps (Google Docs, Google Calendar etc.)
• integrating features from other Google products (an example of an existing feature was the "Open as a Google Document" links placed next to Microsoft Office attachments).

Google didn't mention anything about an interface change, but a recent discovery showed that Gmail also prepares a new UI.

Gmail, Features, Google, Event, Conference