Ratliff gives the Spurs a physical, shotblocking presence as an option for when the Spurs face teams with a more traditional bigman. For a minimum or LLE contract, this isn't a bad acquisition.
Moving forward, the bigman rotation for next season may look like...
Starters
4 Duncan
5 McDyess
Bench
3/4 Haislip
4 Blair
4/5 Mahinmi
5 Ratliff
The Spurs appear to be ready to start the season with 20 year old Blair as the first bigman off the bench. Further, Ian Mahinmi figures to be the 4th bigman, while Pop will have Ratliff to go against bigger frontcourts or if he wants a greater defensive presence inside. Haislip appears to be RC's stab at finding the elusive big 3 who can play both forward spots. I think Gist will be slated for another year in Italy or will spend the season as a Toro. Bonner is on the way out.