Actually for readability, this one's even better,

It has only 32 "words" compared to your 70,

182 non-space characters to your 363,

and runs just as fast:

select

u.UserID

, stuff((

select ', ' + u2.RoleName

from @UserRole u2

where u2.UserID = u.UserID

group by u2.RoleName

order by min(u2.RoleAssignedDate)

for xml path('')

),1,2,'') 'RoleName'

from @UserRole u

group by u.UserID