PBT has some information on the "Shakespeare Street" Giant Eagle redevelopment - not behind a paywall for once!
The basic plan remains the same as was announced awhile ago - the current shopping center will be demolished, with a new, smaller Giant Eagle built fronting on Centre. There will be a 220-unit apartment development mostly along Shady Avenue which will have ground-floor retail broken into many potentially smaller storefronts. The interior of the site will have a 500-unit three-level garage, with half the space dedicated to the apartments, half to the store. This picture shows (in blurry form) a site plan. Strada is apparently the architect. If there will be as much ground floor retail as is suggested, this will be a great thing, essentially creating an entirely new business district, and framing both sides of East Liberty Station with retail.
Some interesting facts were shared by a representative from Pittsburgh for Public Transit about overbuilding of parking in other nearby developments (Target and Eastside Bond apparently have 30% excess capacity) and hopes to redevelop the intersection at Penn to be more pedestrian friendly, but it's unclear if they have anything to do with the plan for the site or were just interjections by the organization.
The Giant Eagle will have to be closed for approximately two years while the redevelopment takes place.