Suggestions by priority

High Priority

• Tree Merging & GEDCOM Import [1] [2] [3] [4]
• Localization: German, Spanish, French, Italian, Portuguese, Russian, Japanese, Swedish,... [5] [6] [7]
• Shared Photo Albums
• Family Forum instead of Tree Discussion [8]
• Advanced Printing Options [9] [10]
• Inherit values from parent/child nodes (Country, City)
• Location of birth & death in Adding interface
• Improving of Flash Add & Edit interface to support typing of "Swe..." and reaching the option for "Sweden"
• Revision History

Medium Priority

• Relationship calculator: Blood relation instead of shortest path [11] [12] [13]
• List of locations
• GEDCOM Export directly to e-mail, automatically every week [14]
• Cause of Death field [15] [16]
• Powerful Statistics, Timelines, Location Index, etc [17] [18] [19] [20] [21]
• Recently logged in users list [22]
• Famous Relative Section

[23] [24] [25] [26] [27]

• Advanced Name Search

[28] [29] [30] [31] [32] [33]

• Ability to link/post relevant documents (I'd put this into the Shared Albums category) [34] [35]
• Soundex Search [36]
• Adoption issue [37] [38]
• Adding a third gender [39] [40] [41] [42]
• Multiple Births [43]

Low Priority

• More power for tree creator [44]
• New Map system [45]
• Reorganize Photo Tabs [46]
• Maiden Names for men [47]
• Facebook Application [48] [49]
• Hebrew (and other) calendar support
• ICQ# for profiles [50]
• MySQL Export & custom queries [51]
• Public (Celebrity) Trees & Animal Spin-Offs [52]