There's a letter in Jan 2010 RadCom about the use of WSPR on 500kHz that advocates keeping the band just for CW. I understand the sentiment, but WSPR is a very narrow band mode taking just 6Hz bandwidth for a single transmission, which may be sent for as little as a few minutes in each hour. Surely there is space for both WSPR and CW? Incidentally I've had several attempts at CW QSOs with quite strong stations on the band and, with a few exceptions, it has been hard to get a contact with my low ERP.
Not so with WSPR as I can get reports (via the database) day and night in great detail - reporting station's callsign, S/N level, distance, QTH locator, direction. All data that confirms the signal has propagated to the distant receiver. It allows me to see in a few minutes the effect of a change of propagation, antenna, ground, power output etc.
Also, take another example (reported in an earlier blog entry) on 40m this week. Noise level here was running at S8-9 and it was a struggle to hear much on the band. I go on to WSPR (running 5W to my 5m long vertical) and get a report within a few minutes from VK4YEH who was 16451kms away. On CW I would never have heard him and I doubt he would have heard me. With WSPR I KNOW that my QRP signal reached Australia.
Like many, I enjoy CW especially with QRP, but there is definitely a place for WSPR on ALL bands as a real means of experimentation with propagation, antennas and rigs.