This is good news for the businesses that use social media. However, it seems unlikely to rekindle interest among ordinary users, who may find list-building tedious, especially with the user interface that Twitter provides.
Lists generated a lot of enthusiasm when they were launched in 2009, because they provide a way to track special interests without cluttering up your timeline by following hundreds or even thousands of extra accounts. For example, I created lists to follow topics such as Microsoft and Security+Antivirus, which follow 269 and 107 Twitter accounts respectively. Checking a list provides a much better view of what's happening in a particular area than the standard timeline view. (Of course, if you don't want to share a list, you can keep it private.)
Twitter Lists are similar to the feeds in Facebook, where people can add their friends to different channels such as Close Friends, Family, Colleagues and so on. They may also have inspired the Circles in Google's G+.
The problem was that while the original parameters (20 lists and 500 members) might have been sufficient for most Twitter users, neither proved to be enough for the long tail of businesses and social media editors, who have been celebrating the new features. One even danced.
But it would be dangerous to think that expanded lists show a renewed interest on Twitter's behalf. Lists were probably much more widely used when they appeared on the home page. However, Twitter consigned them to outer darkness in one of its many redesigns, and it takes three clicks to read a list: go to the Gear wheel; select Lists from pull down menu; scroll down to find your list; click on list name. It's easier to forget they're even there.
There is plenty of room to list Lists down the left hand side of the home page, underneath Trends. Lists could also be added to the menu bar at the top of the page, alongside the Home, Connect and (pointless) #Discover buttons, or added to the tabs after Tweets, Followers and Following. By making lists harder to find, Twitter appears to be deprecating their use.
In addition, it's still relatively hard to add people, because there is no visible "Add to List" button. Users have to click a dropdown arrow, select "Add or Remove from lists…" and then find the appropriate list. Even when you make the effort, the process frequently fails.
Last month's closure of the Listorious website also seems to confirm a continued decline in the popularity of Twitter Lists. As I noted in 2010, Listorious provided a very useful way to find and manage Twitter lists. But it "didn't bring in any revenue", and now the site redirects to Muckrack. This specialises on listing journalists, and is therefore a resource that "communication, marketing and PR pros" may pay for.
Although Twitter Lists are useful for tracking people and topics, you can't do what most social media-oriented businesses would love to do, which is broadcast to them. You can't compile a Twitter list of 5,000 people who are interested in (say) photography and tweet them all a promotional message, you can only pay Twitter for a promoted tweet. This is something that you could do on G+, by compiling a Circle of photographers, though in most other areas, it's probably not be worth the effort.
Still, Twitter and Facebook are now a primary news sources, and most publications -- especially in technology -- tweet all their stories. A curated Twitter list may well be a replacement for RSS.