I am with Ridley on this one. Most of the rules bloat are in the forms of options like PrC and Feats, both of which are sets of rules that are simple to incorporate.
This is not like Options and Powers where you can define how to divide up how you would like that 17 in your STR score be applied....gee lets see do I want to do more damage, or have a better Bend/Bars lift gates score?
Racial levels, alternate class abilities, are specific swapping of abilities that are really not that far akin from something a player might approach a DM with for an alternative ability more in line with their vision of their character.
There are a lot of spells in this version, which one could call bloat, but others would call options, on a personal level, I tend to blank on the new spells from PHB II and Complete Mage.
The only place were you have new rules being welded in wholesale would be the new uses for Skills in the Complete X series, (which frankly I ignore, it is never hard to adjudicate on the fly whether a character with X skill can do Y action to explicitly stated in the rules), the Skill Trick abilities from Complete Scoundrel, and the alternative rules from Unearthed Arcana.
In terms of bloat, you could if you let everything go, (with no restrictions), wind up with a character with Flaws and Bloodlines fromUnearthed Arcana, perhaps a dragon influenced race from Dragon Magic , Psionic Feats and Incarnum Feats, and some Martial adept feats from Bo9s, levels in the wonderfully overlapping classes of Wilderness Rogue and Scout, with the feat from Complete Scoundrel that lets you combine the levels of both classes together for certain class abilities, and then throw in some substitution abilities from PHB II or other books.
Funny part is even with all of that madness, you still wind up with a viable character that is easily adjudicated, even if the rest of the group was using 'vanilla' PHB only characters.