You can create a reference to the enum in your component class (I just changed the initial character to be lower-case) and then use that reference from the template (plunker):

import {Component} from 'angular2/core';

enum CellType {Text, Placeholder}
class Cell {
  constructor(public text: string, public type: CellType) {}
}
@Component({
  selector: 'my-app',
  template: `
    <div [ngSwitch]="cell.type">
      <div *ngSwitchWhen="cellType.Text">
        {{cell.text}}
      </div>
      <div *ngSwitchWhen="cellType.Placeholder">
        Placeholder
      </div>
    </div>
    <button (click)="setType(cellType.Text)">Text</button>
    <button (click)="setType(cellType.Placeholder)">Placeholder</button>
  `,
})
export default class AppComponent {

  // Store a reference to the enum
  cellType = CellType;
  public cell: Cell;

  constructor() {
    this.cell = new Cell("Hello", CellType.Text)
  }

  setType(type: CellType) {
    this.cell.type = type;
  }
}

You can create a reference to the enum in your component class (I just changed the initial character to be lower-case) and then use that reference from the template (plunker):

import {Component} from 'angular2/core';

enum CellType {Text, Placeholder}
class Cell {
  constructor(public text: string, public type: CellType) {}
}
@Component({
  selector: 'my-app',
  template: `
    <div [ngSwitch]="cell.type">
      <div *ngSwitchCase="cellType.Text">
        {{cell.text}}
      </div>
      <div *ngSwitchCase="cellType.Placeholder">
        Placeholder
      </div>
    </div>
    <button (click)="setType(cellType.Text)">Text</button>
    <button (click)="setType(cellType.Placeholder)">Placeholder</button>
  `,
})
export default class AppComponent {

  // Store a reference to the enum
  cellType = CellType;
  public cell: Cell;

  constructor() {
    this.cell = new Cell("Hello", CellType.Text)
  }

  setType(type: CellType) {
    this.cell.type = type;
  }
}