From the introduction:
I started out with the ambition of changing the 4th Edition adventure series H1: Keep on the Shadowfell, H2: Thunderspire Labyrinths, and H3: Pyramid of Shadows – as there was very little in the plotline that really tied these adventures together into a full story.
Having just finished up the conversion of P3 i think E1, E2 and E3 is very well tied into the overall Orcus plotline, so there is no greater need for any adjustments. However, I will look into updating the monsters to the new formats introduced in Monsters Vault. Other than that I might just do some add ons if I feel it would add value to the story or introduce some new exciting elements.
Please note that you should read through P1 to P3 Conversion Guides first, as it gives you the full background story to the campaign.