Hmm, While I do like the omnitool for vanilla IC2 stuff (Gregs wrenches manage faces in a completely retarded manner, I still haven't figured out how they work) the concept of a tool unification seems to have a flaw. What if a modder WANTED you to EXCLUSIVELY use their tools as they have balanced their mod around or partially on the tool.
For example GregTech; He made it so his automatic machines can only be picked up by his wrenches that have limited durability becasue he's under the impression that moving machines require a cost.
Just say other modders took this approach. This would be incredibly stupid of course, but if enough modders opted out and or coded counter measures forbidding omnitool interaction we'd be back to square one many different mods with many different tools.
Sure KL could hack around the counter measures but this has caused 'friction' in the past that sane people would try their best to avoid.
Another example is Thaumcrafts wand, this has no omnitool interaction/ support and probably never will, but it is an example of a tool that the mod is balanced around.
If KingLemming was willing he could allow the Omnitool to interact with TC for creating crusibles, reclaiming golems, repositioning arcane bores crafting and make it store or not require Vis to operate. But this in turn would mess with the mods balance and in 1.6 it would screw with some core mechanics. So it's more tactful to not allow interaction that ant it just doesn't fit the theme.
If other mods decide to elaborate and balance around their mods tool, tool unification would just become useless.
Of course this is based on a lot of 'IFs', But it's a potential problem. That being said the omnitool is VERY handy for most tech mods in 1.5 mods and will be sorely missed in 1.6 an onwards.