The "All blog updates" list in the Reading List is incomplete!and
My Blogger Dashboard display only goes back a few hours!!
The complaints involve only the aggregated content of the blogs displayed individually, under the Blogs column in the Reading List, as "All blog updates". The individual blog content, as displayed separately, do not appear to be affected.
We have a rollup discussion, in Blogger Help Forum: Something Is Broken, where the details of this issue are being discussed. This problem was originally reported on or before 2/25/2011, and the discussion itself was opened on that date. On 3/2/2011, Blogger acknowledged the problem, and implied that a resolution would be coming.
We're working through this right now and will report back as soon as we have more information to share. I believe this is related to a recent code change we made.
(Update 3/9): Blogger Support provides a terse update.
We've identified the source of this problem and will have a fix out shortly which will restore all of the Reading List content.