Currently, there is no way to change the text of the property label and we think that it's not a good solution. Instead of this we are planning to add an ability for users to create custom friendly control editors (wizards) for their custom controls. For example, when a user goes to edit a control and if the control has such friendly editor, it will appear in the property dialog, still the user (most commonly, a developer) will be able to switch to the the advanced property editor, which is the current one. We prefer this, because the developers are used to see the original names of the properties when editing a control (like in Visual Studio), and on the other hand, the non-developers will be able to use more friendly editors.
This feature is planned for Sitefinity 3.1.