I'm glad someone got around to posting this up on the PA forum. It was my intention to do as I had done on the NYS forum, but I haven't had the chance to get to it!
To answer your question, the siding at Catawissa is currently in the planning stages between NS and CP engineering officials. From what I was told, the hope was to have the siding in service by the end of this year but it sounds like it will more likely happen next year. Still no word on the exact location, however it is supposed to be a 10,000' signalled controlled siding just like the Sidings at New Milford, Dalton and Hanover. This will really improve operations South of Dupont. Even with the 6 or so trains a day now (with more to come), trains can take up to a 45 min to 1 hr delay waiting for another train at Banks and or Nescopeck.
Additionally after a recent day railfanning the Sunbury Sub between Binghamton and Nescopeck, I observed a good bit of new welded rail layed out in a number of locations along with large piles of new tie plates and spikes. The most significant amount of rail I saw dumped was at Hop Bottom (CPF 648). It appears as if they are finally going to do a much needed upgrade on that section of the railroad, maybe finally to knock off the 25 mph speed restriction b/w 648 and 650. It still amazes that the Sunbury Sub still has about 10 or so miles of jointed rail on the segment between Buttonwood (M.P. 692) and Hop Bottom (CPF 648). It would take about 1 rail train worth of CWR to get rid of all the jointed rail, but it still hasnt happend (just my 2 pennies though)...
From what I was told, also look for a tie project and some surfacing/ballast and regulating work this season as well.
In theory (with PTC requirments approaching quickly) CP should be starting on the CTC (PTC) project on the Sunbury Sub this year as well, but I have heard nothing about it yet.
For anyone interested, I have a yahoo group dedicated to the CP Sunbury Sub. Heres the link if anyone is interested in joining and learning more about the line: http://groups.yahoo.com/group/cprsunburysub/