It is very useful to us to have a year to date tax summary available on each donor's profile, in addition to the previous few years. This exists in Kindful, but doesn't in Bloomerang (we just converted from KF to BL). We send current year tax summaries to donors before the year is over for a variety of reasons, including asking them to request matching funds from their employer and the year to date summary is acceptable proof of what they have donated.
Yes this would be very helpful! We also have donors requesting reports of what they have given year to date. The email I was able to put together doesn't look nearly as nice as the Year End Giving Summary that Bloomerang has for previous years.