Compare the background. The old Nickelodeon logo included an orange splat background, which was completely removed from the new logo.
Review the colors. The old Nickelodeon used white lettering for text, but the new logo uses bright, orange letters.
Inspect the text case. The old Nickelodeon logo used uppercase throughout, but new logo only uses only lowercase letters.
Study the fonts. A Balloon type font was used for the old logo, but the new logo uses a custom made font. In addition, the dot in the letter "i" connects to the bottom of the letter.
Analyze the overall design. The old logo was a combination of text and graphics, whereas the new logo is type only.