Since I had to travel the Mass Pike from Weston to the NY border to attend the Capital District Road Meet in Albany on Saturday, I took notes along the way on any progress seen on the I-90 sign replacement contracts. From the 7% complete listing for the western project and nothing for the eastern, I wasn't expecting to see much, but there were some things to note.
On the eastern section, the only evidence for the project were orange tags placed by the contractor, Liddell Bros., to mark future sign locations, such as here for the 1-Mile Advance for MA 9 in Framingham:

These tags, however, only were placed between I-95 and I-495.
In the western project area there were no indications of any sign project at all. The only contract related work that could be seen were the placement of the new 2/10 mile reference posts, and these were only seen starting at Mile 40 westward. Here's one of the few right-hand markers, the rest were in the center median, where there is an older cement median just east of the Westfield River:

These markers are not of the design depicted in the project plans, the same as on all other MA interstates, but have larger vertical numbering.
The only new signs seen on the Pike were the new MassDOT 'Go Time' travel time signs, and not all of them have been placed yet. Here's the sign approaching I-495 westbound:

Photos of other new travel time signs on the Pike and I-95/128 taken on Saturday 9/24 can be found in Section B of the Misc. Massachusetts Sign page:
http://www.gribblenation.net/mass21/miscsigns.html