There are new Rare and Incomparable Vanguard Runes that drop in the instances and raid and have different effects. The rares have been selling for 200g, the incomparable for 2000g+.
There are three types: Striking increases Base Combat Damage Modifier, Enchantment increases Tactical Damage Rating, and Binding increases Tactical Healing Rating. The rare version increases these by 76.8, the incomparable by 96.
Unfortunately, it is not clear what number they are actually increasing. Adding 76.8 to 1415 (which seems to be the case for my hunter's bow) is not as significant as adding it to 206.5 (which seems to be the case for my minstrel's songbook).
I posted a couple messages in the LOTRO forums about this. In case you missed them, here are the basic results.
For Michaleo's bow, I did careful measurements of actual damage and compared it to the differences in the numbers in the skill tooltips to show that the actual damage increase was consistent with the tooltips. It is much more difficult to do the same comparisons for healing skills, so I just assumed the tooltips would be consistent with actual heals.
The Rune of Striking in the bow increased the DPS and damage number shown on the LI by 5.4%, but no skills actually increased that much. Penetrating Shot and Barrage were 1-2%. Although the initial damage from Barbed Arrow increased 4%, the bleeds from this and other skills are not affected by the Rune of Striking. Since none of my favorite skills had much of an improvement, the Last Alliance Rune of Force with 4264 Physical Mastery is a better choice, since that increased skill damage more and by the same percentage for all skills including bleeds.
The Rune of Enchantment on my minstrel's weapon had a 7-16% increase in damage, depending on the skill. This amount is greater than you would get from the Tactical Mastery in the Last Alliance Rune of Power, so it is worth getting. Because the DPS and damage range on the sword is for the physical damage from the strike skill, I couldn't guess what number was increased by 76.8.
The Rune of Binding had a much bigger impact. In this case, the base number seems to be 206.5 for a maxed songbook. +76.8 is a 37% increase, and most skills showed that. Soliloquy of Spirit was somewhat less, and Fellowship's Heart was only 3%. A second Rune of Binding in the weapon increased it a further 27%! Since the weapon has a damage rating, not a healing rating, this was a surprise. Two runes of binding are definitely worth it. If you don't have separate weapons for healing and damage, you'll have to decide whether you want the increase in damage or the increase in healing.
For a guardian, the Rune of Striking has a 4-5% increase in 2H DPS, but 6-7% increase in 1H DPS, since the base DPS is lower and it adds a fixed amount. Unfortunately, it does not increase bleeds, which are usually an important part of guardian damage. It does nothing for shield skills, and you lose the 3% from the Physical Mastery in the rune it replaced. Surprisingly, the Rune of Enchantment in the guardian belt increases shield damage by 24%. Because it works like the Rune of Binding for minstrels, you can put a second one in your weapon to get another 20% for a total of almost 50% more shield damage versus the 6% non-shield and bleed damage you lose because of the loss of Physical Mastery.
The LOTRO forums have a variety of claims about these runes. They seem to be class dependent and vary from skill to skill. If you are going to slot one, please jot down the tooltip numbers for your favorite skills before and after to see if you get similar or different results and let us know.