The names are now rendered as hyperlinks and you can click first or last name to access the underlying record.

When importing leads the match option can be selected. Matching on email address will prevent duplicates. Additionally, when you convert a lead you are presented with a screen asking which objects (Person, Organisation, Opportunity) you wish to create. If a similar Person or Organisation already exists they will be displayed in the “duplicate” list.
Having said that, we are aware of the requirement to merge records. Typos, and the human factor will always have potential to allow duplicates to be created. When this happens a merge would be very handy to merge notes, emails etc onto one record.

We are implementing a Process Engine solution to deliver similar functionality in a flexible solution. It will be targeted at Sales Lead and People de-duplication.
(#2537)

Apologies for the delay in updating this idea. This feature was released earlier this month. MailChimp integration is currently being developed and due later this year.

Documentation here:
http://www.workbooks.com/help/mailshots