Add in a way to either fill in the next available id for items and blocks with minecraft forge allowing more mods to be compatable, or making new arrays for each named after the modid.

 

Benefits of the first is that each mod would just fill in the next available id instead of being set that way you dont have to move the id numbers super far ahead or change them to make them compatible with other mods. Only problem is that two or more mods may try to fill the same ids repeatedly.

 

The second means far more compatibility since you would have your own array of ids rather than having to use the same array as minecraft and every mod. This would allow potentially endless items and blocks without having to continually extend the regular arrays, The only downside I could see is after creating a dozen of them minecraft may have problems loading each one individually. Perhaps each mod extends the existing array by a certain amount automatically offsetting your ids.

1) IDs are going away 2) We already have that in place, modders dont use it.