With the introduction of CiviAccounts in CiviCRM 4.3 the ground work to allow CiviCRM to cater for Tax against contributions has been laid.
During the week-long sprint in northern California following CiviCon, we've been working through the design and amendments required to complete the implementation of Tax within CiviCRM.
The specification can be found on the wiki
For those of us that have tried CiviReport with ACL's and custom data, we'll be aware of the issue that in order to use the custom data in reports the user must have Access All Custom Data privilege enabled. This is not the desired functionality and thanks to funding from Leukaemia & Lymphoma Research a patch is available which cures the problem, allowing you to use ACL's with Custom data without compromising the CiviReport functionality.
You can get the patch from the following JIRA issue
Here at The Leukaemia & Lymphoma Research charity, a lot of events have participants who may be children or where a team leader is booking for all team members. The current implementation of CiviCRM insists on the inclusion of an email address for all participants, which is a problem in the two scenario's. Some of the teams are quite large and each team member has specific settings which need to be captured, such as t-shirt size, route etc.