Talk about an issue I didn't even know existed. In The Original Meaning of the Recess Appointments Clause, Lawprof Michael B. Rappaport (who's also a contributor to The Right Coast blog) argues that two aspects of the present interpretation of the Recess Appointments Clause are inconsistent with the original understanding of the Clause:
First, I maintain that the original meaning permits recess appointments to be made only for an office that becomes vacant during the recess when the recess appointment is to be made. If an office becomes vacant while the Senate is in session, or if it becomes vacant during an earlier recess and remains vacant during the Senate session, the President is not permitted to make a recess appointment to that office. In essence, if an office is vacant while the Senate is in session, the Constitution expects the President to make an advice and consent appointment at that time. By contrast, under the current interpretation, the President can make a recess appointment for any office that happens to be vacant during the recess, irrespective of whether the office was ever vacant while the Senate was in session. Consequently, the current interpretation allows the President to make a recess appointment to an office that had first become vacant several years before the recess. The President could also recess appoint an individual who has been nominated for an advice and consent appointment, but who now seems unlikely to secure senatorial consent.
The second issue on which the current interpretation departs from the original meaning is the definition of a recess. The Congress has traditionally held one legislative session per year, which is followed by a recess that lasts until the next session. This recess between the legislative sessions is called an intersession recess. By contrast, Congress also holds recesses during the legislative session, which are called intrasession recesses. I argue that the original meaning allows recess appointments to be made only during intersession recesses. In the early years under the Constitution, intersession recesses typically lasted between 6 and 9 months and therefore recess appointments were needed to prevent important offices from remaining unfilled during these long recesses. The current interpretations of the Clause, however, allow recess appointments during intrasession recess. These intrasession recesses are often extremely short, although there is a disagreement over whether recess appointments should be available during all intrasession recesses or only those that last a minimum time, such as two weeks. In either case, though, the current interpretation would allow recess appointments to be made during recesses that seem far too brief to justify bypassing the Senate.
I haven't read Prof. Rappaport's paper yet, but it looks like an interesting subject.