Zak Penn, who has worked on The Avengers, is working on another Marvel movie. The MCU has grown a lot over its first 10 years. However, this is only the beginning. Given that Disney has bought Fox and the Marvel properties being held by Fox, this could mean that it is going to get a lot bigger after Avengers 3 and 4. This could mean that at some point the X-Men and the Fantastic Four might join the universe. There are also some big villains that can appear after Thanos is taken care of. There might be Galactus as the next big baddie.
To go along with the next Marvel movie, there is talks of a possible reboot of The Matrix franchise. While the original 1999 film has impressed audiences at the time of release, there is probably no need for a reboot. By the time it has gone to the third film, the popularity of the franchise has died down by a lot. One of the issues with the trilogy is the direction that they went with the story after the first one.
While The Matrix has had its time to shine, there is still room for Marvel with tons of characters they can explore. Disney and Marvel has revealed their plans for Marvel characters over the next few decades. Therefore, they have a lot of stories that they can tell. There are also plenty of potential ideas for crossovers. Given that characters that have some kind of history with Marvel, but are not necessarily Marvel characters can join. For instance, it would be very interesting to see where the Transformers would fit. Imagine Galactus and Unicron.