Monkey Island was originally done by LucasArts. So in a way, it's similar to what we are debating right now (if hypothetically Phoenix Online were to get the rights to Sierra's games). I liked the new environment and the different atmosphere that Monkey Island was known for. Telltale games brought back an old cast as well as introduce new faces. However, I was overall disappointed with the ending (not going to spoil anything). So Telltale Games took a series that wasn't theirs and tried to establish themselves as a game developer by putting their spin on it. Would it be wise to completely disregard any other game that they attempt to make? Hardly. If anything, it'd be wise to pay close attention to them. Cause while I can sit back and point out the flaws, I can easily sit back and ponder the advantages that the game had.
Actually to be fair, this is not a good analogy btw. You are looking in the wrong direction.
Tales of Monkey Island was a game jointly produced by Lucasarts and Tell Tale games (its not the first time Lucasarts has worked with 3rd party companies in the past, BTW). Don't believe this, I suggest you look at the logo screen again. Telltale didn't buy the franchise from Lucasarts. I don't think Lucasarts would ever would sell it as it is one of there most popular IPs.
Also many of the people involved with that game were the original people behind earlier Lucasarts and Monkey Island games (they even consulted Ron Gilbert who hadn't been involved with the series since MI2, and by later episodes he was directly involved). You might not know this but many of the designers of Tell Tale originally worked at Lucasarts on the Lucasarts adventures. So its essentially what became of Lucasarts adventure division. Its not exactly "another unrelated company taking over the IP". Its people with experience with those IPs, and should have the right to continue those IPs. For that matter, they even were able to get many of the same actors from CMI to reprise there roles.
Now me personally I think I kinda agree with DMD on this particular issue, I don't so much care if a third party creates an official continuation of an adventure game series, but I think its important that some of the original designers behind the IP is involved with making the games. Even games that stayed with the company such as last 2-3 Leisure Suit Larry games aren't as good as the originals, mainly due in part because they didn't have Al Lowe's involvement. He really is the only one that knows that franchise. As I understand it another company now has the right to that series, their first game using the IP was just as abysmal as the first non Al Lowe version, if not worse. Although personally its not really my cup of tea as far as the Sierraventures. Or the Dr. Brain series, the later games which lacked Lori and Corey Cole's involvement, pale in comparison to the two original games in the series.
There are MI fans that argue that Curse of Monkey Island and Escape of Monkey Island are not essentially authentic games in the series because they lacked Ron Gilbert's hand. Thus for many it was important that he returned for Tales of Monkey Island.
With Space Quest, I'd want Scott Murphy, Mark Crow, or at least Josh Mandel behind the game and its story. Jane Jensen would have to be behind a new Gabriel Knight, etc. I mean more than a just a "blessing" (however congratulations would have to be in order for that honor).
Without the direct involvement of the original writers and designers the game has the potential of being only poorly conceived derivitive work (the crappy LSL come to mind) at best a "spiritual successor". Another case in point look at the latter Simon the Sorcerers, a German company bought the IP from Adventuresoft, they destroyed several aspects of the series, for example they made Simon, American, when he was originally British... I've heard that there are actually other continuity issues between the classic series and the later sequels.
