You should not need the DP44, unless...
Since you are going from 3 orbital locations (61.5/110/119) to 3 orbital locations (110/119/129) your existing switch should work fine. Things that could require upgrading to a DP44:
* viewing all four of those orbital locations, or
* using single cable with a DP Separator (requires DPP technology - i.e. DP44)
Good luck!
As an aside, I ordered my HD equip upgrade today. The sales tech said I would need a new dish for 129. I pointed out to him that since HD programming is mirrored on 61.5 and I already have 61.5 that I would not need the new dish. He claimed that not all programming was mirrored, but after checking on that he corrected himself saying there is only one HD channel on 129 that is not mirrored to 61.5. In the end, I am allowing the dish 1000 upgrade since it will not cost me any more than I am already paying and should net me a DP44 in the process. If it turns out otherwise when the installer arrives, I'll keep my existing dishes. And being a new install, I will use the install warranty to pursue any 129 issues I may encounter.
Cheers,
Red