As noted above JIRA Agile 6.6 introduces the custom cards feature which allows up to 3 additional fields in each plan and work modes.
One of these can be the assignee name so can be used as a solution for this issue. I will now resolve this issue.

The release notes can be found at https://confluence.atlassian.com/display/AGILE/JIRA+Agile+6.6+Release+Notes
and a blog post on the features at
http://blogs.atlassian.com/2014/09/jira-agile-6-6-now-available/

Regards,
Martin
JIRA Agile

It's solved in agile 6.6

Firstinitial Avatar - dont you think there could be more than one person having an initial?! I really wonder what this improvement is worth. At least, you should take more than one letter, or you should offer to set a short abbreviation for any user (what most of the companies do have for their employees). One letter is just not enough and Jira should not be a tool for kindergarden but for business. I like the avatar pic like it could make sense for very small teams/companies, but you have to show the real fact data or a unique abbreviation of it aside or instead of the avatar.

Thanks for your feedback on the first-letter avatars. These avatars do help some customers who prefer a highly visual indicator of assignment, in particular those that cannot or do not upload or select images. As noted above the request for the assignee name is not yet fulfilled and so this issue will not be resolved yet.
Regards,
JIRA Agile team

https://confluence.atlassian.com/display/AGILE/JIRA+Agile+6.3.11+Release+Notes#JIRAAgile6.3.11ReleaseNotes-"Firstinitial"avatars

On the old agile boards it's really nice being able to CTRL+F and start typing a name and finding what's assigned to them - echoing the sentiments that the avatar thing really isn't useful for my environment.

Our company cannot upgrade to the new Jira Agile until this issue is resolved. As a project manager, I MUST SEE the name of a person assigned to a story. Not a photo, not an avatar, not a first initial, but the actual name of the person assigned to the story. This is the first objective for all project planning: Knowing who is assigned to what task. Hiding that info behind avatars does not give me more information, it gives me far less.

Avatar without full name has no value for our teams. It is impossible for us to use Jira Agile in current way. Single letter instead of full name has no value added and it's waste of your effort. I miss the "classic" feature: full name displayed - if I click on it I can change the assignee.

Addition of name of assigned resource would be a huge win for our teams. We are very distributed.....

This issue is regarding the representation of the assignee on the card, please vote, watch or comment on card size on the following issue: https://jira.atlassian.com/browse/GHS-5200

Actually, our team does not understand the benefit of the rapid board card layouts (increased font size, avatar picture) in comparison to the CSS layout used in the classic boards. Therein, the planning mode was consistently used with "bar" style issues, while in the work mode, the "card" style was used consistently. In that layout, many more information could be displayed because of the good (but simple) card layout with small fonts. We never had any problems with a too small font size, while in the rapid boards, we do have complaints, e.g. on Laptops with a 16:9 screen, which fails to display more than 4-5 cards even in plan mode. This is definitely not a good layout to get a good overview.