The following is the current list of new features and fixes being implemented into WHMCS Version 2.5. There is currently no release date set for this release. The list is a raw list - written as I've noted down requests - so there is no particular order and some items may not make it to the final release.

Add Nameserver Fields on Domain Order Form
MaxMind Fraud Protection
Offline CC Processing
BluePay CC Processing
Order Form - Remove Javascript Validate on Order Form for Promo - Change to PHP
Prorated Billing (1st, 15th & 30th)
Reorder Payment Gateway Options
Send Invoice Items List in Email
Change Default Server when Server Limit is reached
Make custom fields show * if required
Check invoice gateways don't open new window
Modify Support Operators View of System
Template Monster API?
Fix Bug on Standard Order Form where Step 1 is Confirm Order when No Domain Options shown
Automatic Termination x days after non-payment
Add Fee onto late invoices
Pending Orders Pruning after x days unpaid
Affiliates Pending Accounts Page?
Stop Affiliates Referring themselves
Support tickets with newest responses at the bottom of list (https://whmcs.com/forums/viewtopic.php?p=1232#1232)
Image Verification on Order to prevent bots
Domain allows a "." in the field box?
WHOIS Storing Stats
Block users IP for 15 minutes after 3 invalid login attempts
Add option to display verification image on admin login
Add Remember Me to Client Area login
Support to Offer Free Domain with certain Payment Terms
If you click on Mark Paid, then Cancel, it still marks it as Paid.
Support to change invoice back from Paid to Unpaid or Cancelled
Prevent Invoice Creation with no invoice gateways enabled
Remove dashes from phone number before passing to DirectI (Validation Req.)
Surpress Latest Version Retrieval Errors on Admin Homepage
Add Support to View MRTG Bandwidth Graphs with Dedicated Servers
Add Fields for Rack Location to Dedicated Servers and Assigned IP Range
Support Ticket Departments
Improved Mail Piping Handling with Support to Pipe to Different Departments
Add Custom Fields to Support Tickets
Record Domain Registration Type (Register or Transfer)
Remove Amount Due from Upcoming Domain Renewals List
Display Calculated Order Summary on Signup/Login Page of Order Form
DirectAdmin Support
Add support to allow moving a domain, hosting account or product/service to another clients profile
Prevent ordering a domain already in the system - not if set to Terminated
Suspend Resellers Clients when suspending reseller account
Highlight Disk Usage Line on Report if usage over 80%
Fix Language Selection Dropdown after choosing another langauge - stays on default
Add Generate Invoices Button to Admin Side to generate invoice instantly after adding account
List accounts subscription reminders are sent to in cron report
Add support to re-order payment gateways on the order form