As did I-but for the OP I think there might be a slower development of long-distance steamships. The Great Western was the first transatlantic liner, and the Great Britain, though an economic failure (actually converted into a sailing ship) was the progenitor of most passenger or cargo liners: iron hull, steam engine and screw propulsion. While Brunel was neither directly responsible for these innovations nor a naval architect, he was the sort of 'big picture' thinker, (or systems engineer, in a later parlance) required to combine nascent nautical developments. Steamships would be developed in a slower and somewhat piecemeal fashion without him, especially because the mid-19th was a less bureaucratic era.