Heritage staff at the City wanted to save at least one of the Dickinson towers. There were a host of problems/additional costs associated with saving even one of them, but Heritage persisted, and got some support among heritage advocates (I believe John Bentley Mays wrote a column in support at one point). When it went to Toronto East York Community Council, however, dozens of Regent Park residents and non-residents showed up to essentially say "are you nuts?!?" A friend of mine was present at the meeting, and she said the general gist of most of their comments was, notwithstanding the interest shown by a bunch of privileged, white armchair heritage buffs, none of whom actually had lived in Regent Park, these buildings were not great for the residents for a long list of reasons. The residents didn't love them the same way Heritage staff did. Council listened to the residents.
What is mostly left are a number of the red-brick buildings in Regent Park North. About 10 years ago now, I went on a TCHC tour of each of the building types in both Regent Park North and Regent Park South. The red-brick walk-ups in RG North were in terrible shape, compared to the various unit types in RG South, and did not seem like appealing housing. Even the balconies were dank and badly designed. My short tour does not give me the experience of actually living in those units, so I might be off the mark, but my brief exposure did not suggest that there was anything worth saving - even the exteriors (given the building placement and design). As suggested above, I'd far prefer that they save some of the red brick and incorporate it into some sort of commemoration, rather than saving a token building.
It does appear that they will save a small block of Regent Park South townhouses - the ones on the NE corner of Shuter and Regent. Most of that block stayed in private hands during the original Regent Park redevelopments of the 1950s and 1960s (likely due to the fact that (what is now) St George's Macedonian Bulgarian Eastern Orthodox Church seems to occupy/own most of the block), except for that one corner which got redeveloped along with Regent Park South in the 1960s. There might not be a business case to redevelop that small parcel today, so the old townhouses remain. Correct me if I am wrong, but I believe those townhouses are the last remaining Regent Park South 1960s architecture.