right now it's possible to show additional information e.g. on artists in an fpane by switching on the "show info" option.
this produces the following output:
Artist (Year - Year)
$n songs, $totaltime

to be honest the total playtime is not the most useful information i can imagine there. but if people like it, it's ok i guess.
i would add the album-count to the second line like this:
$n albums, $n songs, $totaltime

the smaller the number, the easier to grasp how much i have of an artist. also: in my current layout i don't display the number of albums anywhere so it would be extra useful information.
(i assumed the "info" column is hardcoded, or is there a way to customize this in a layout?)

Yes, I've planned to add customization of this for a long time.
I'm working on something that will, among other things, change the syntax used, I'll probably add a way to edit the format string after it's done.
Meanwhile, you can change it in the source file (gmusicbrowser_list.pm), only a few fields are available, the default format string used is :
"<b>%a</b>%Y\n<small>%s <small>%l</small></small>"
You can add %x that will be replaced by "n albums" (or "n artists" for albums)
or %X that is the same as %x but "1 artist" is not shown (this is what is used in AABoxes)
(by the way, this also work in v1.0.x)

btw, it's a tiny bit inconsistent to have "$n Album/s" with a capital "A" and "$n song/s"...
other than that i like it even more now that i removed the totaltime -> less info, easier to read.