IMPORTANT! Please refrain from re-posting this on the Wizards community forums. It can be viewed as inappropriate for a company to talk about their products on another company's forums, so we won't encourage that on the Wizards forums. That also means we won't answer questions posted on the Wizards forums. You are welcome to post a link to this thread if you wish, and please encourage anyone with questions to ask them here on our forums so we can provide answers.
Now on to your questions....
There is no formal license in place with Wizards for our support of D&D 4E - it's the lone exception out of all the games we support. That being said, we've had a good relationship with Wizards for about eight years now (dating back to our Card Vault product well before Hero Lab existed), and our Hero Lab support for 4E has been in place for almost two years now. So we're not anticipating any problems with how Hero Lab works vis-a-vis 4E. Allow me to provide some background and delve into this topic further....
Our working relationship with Wizards began back in late 2002 after we released Card Vault. We obtained permission from Wizards to support all of their CCGs, including advance access to the spoiler data for all those games. We've never had a formal license in place for this, but Wizards has been providing us with that data for 8 years now. They did so even though they had the Magic Online product for which Card Vault could be construed as competition.
When we first started supporting 4E (almost two years ago), we spoke with a senior Wizards staff member about what we were doing. And then we had a follow-up discussion with another senior Wizards staff member a few months after that. In those discussions, we outlined to Wizards how Hero Lab's use of the DDI content required that a valid DDI account be used, which thereby makes it an add-on to DDI and not a replacement. Given the wealth of new content introduced every month by DDI, continued access to that new content entailed an ongoing subscription. That's how Hero Lab has operated for two years now, with Wizards' full knowledge.
During the past two years, Hero Lab has offered a few key abilities over and above what the Character Builder provided. These include (a) the ability to add custom (home-brew) content, (b) convenience as an electronic character sheet at the table with extensive in-play adjustments, and (c) the Tactical Console for GMs to efficiently run encounters. With the new announcement by Wizards that DDI is switching to a purely online solution, Hero Lab has garnered more attention for 4E than before because it will now allow users to continue enjoying offline access with their characters.
So I guess the big question is whether this change in Wizards' strategy will result in a change to how Wizards views Hero Lab. I'll be surprised if it does, since Wizards would have to suddenly view Hero Lab as direct competition that could potentially threaten DDI instead of as a value-added option over and above DDI. On the flip side, all the Wizards staff we've talked to in the past are no longer with the company, so anything is possible.
Since I think the primary goal of your questions is to assess how "safe" Hero Lab is, let's look at what could happen if Wizards changes their view of Hero Lab. The Hero Lab product itself is completely safe - only it's support for 4E could be challenged. I believe the 4E data files themselves should be fine, as they only support the basic game mechanics and not Wizards' D&D content. Based on this, the worst case scenario for Hero Lab users of 4E would be that we have to stop supporting the downloader tool in-house - to my knowledge, that's the only thing Wizards could POSSIBLY insist we stop doing. However, all the code for the downloader tool is public domain, so any 4E player with a little programming knowledge could continue adapting it each month as the compendium is updated. To the best of my knowledge, that's the worst case scenario here, and it presumes Wizards suddenly changes their position towards Hero Lab after two years.
Hopefully, this answers your questions sufficiently. If you have additional questions, please post them here and I'll do my best to answer them.
Thanks, Rob