Interesting thinky thoughts (hey, it's early). I looked at the moment in the bar as the start of Jack's healing, that this was the moment when he was willing to open himself up again. Because Jack's like the Doctor in that way: he long outlives those he loves and he knows he's going to have to do that. In a sense, the Doctor's saying, "Don't be alone." (Hopefully, the Doctor himself has learned that lesson.)

I didn't see Alonso as being a new regular for TW S4 (for one thing, I think Russell Tovey has other irons in the fire), but I was glad for that moment of healing and Jack looking much happier at the end of the scene than he had at the beginning.

Thinking another thing, though, if you take the idea that the woman on the platform was Susan, the Doctor's granddaughter (and the woman in white who appears to Wilf the White Guardian taking Susan's form), then we have an interesting thread here. The Doctor condemned his own granddaughter to destruction along with Gallifrey to stop the Time War. Jack caused the death of his grandson to save the children of the world. And although Wilf has Donna, he knows how much she's lost by losing her memories of the Doctor. In some ways, it's the sins of the fathers coming to rest on the children.

But the scene in the bar was marvelous, the Doctor just barely touching Jack's life once more. Plus, drunken adipose, which is always fun.