Yep. I didn't catch the extra MKOBJDIR on the dylib rule because the arm object rules were already creating it for me 
. This is correct though.
Don't forget to rename OBJDIR on those two other rules too:
$(OBJDIR)/%.o : %.c | MKOBJDIR DEPDIR
mkdir -p `dirname $@`
$(CC) -c $(CPFLAGS) -I . $(INCDIR) $< -o $@
$(OBJDIR)/%.o : %.s | MKOBJDIR DEPDIR
$(AS) -c $(ASFLAGS) $< -o $@
and just for completion's sake, I would also separate DEPDIR into DEPDIR and MKDEPDIR.
Thanks! 